This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 within the LDRD program.

폴리 셔 및 슬러리 1. 준비 먼저 집중적 인 연마 시스템 준비 (나는 독립 표면 nitial, 특히 C의 onvergent라고 불리는, S 화롯불 반복, R의 ogue 입자 - 무료 폴리 셔 또는 CISR (발음 &#39;가위&#39;)) 패드 및 격막 조절 패드를 설치하여 7,17, 희석 및 화학적 슬러리를 안정화하고, 여과 시스템 내의 슬러리를 통합. <ol><li> CISR 폴리 셔에, 화강암 무릎베이스 상에 폴리 우레탄 패드를 준수합니다. 하나의 가장자리를 제 1 패드 부착되어 에어 갭을 최소화하는 대향 에지를 향해 방향으로 압력을 적용한다. 돌출 된 패드를 잘라서 천공하고 필요하다면 기포를 제거하는 면도날과 롤러를 사용한다. </li><li> 처음 사용하기 위해 모든 ~ 100 시간 후CMP 다이아몬드 컨디셔너를 사용하여 패드, 다이아몬드 연마 조건의 R (50mm 직경은 0.6 psi의 압력을 적용, 5 분 체류를 25mm 간격 단위로 각 반경 무릎 위치에서, 무릎 회전 25 RPM) 흐르는 DI 물. </li><li> 흐르는 DI 물, 연마 반복 사이에 현장 초음파 세척기 (무릎 회전 rpm으로 5 ~ 각 반경 위치에서 2 분 드웰)를 사용하여 패드에서 잔류 슬러리 및 유리 제품을 제거합니다. </li><li> 독특한 모양의 격막의 무게에, ​​양면 폼 테이프 후 격벽 재료 (예를 들면, 프리 컷 유리 또는 다른 비 착용 재료)를 준수합니다. 격벽 재료와 가중치의 형상과 일치하도록 돌출 폼 테이프 트림. 격막 디자인 (형태와 무게 모두) 워크 랩 7,17의 다른 크기에 대한 변경을합니다. </li><li> 부피 혼합 구체적으로 (보메 4 농도에 슬러리를 연마 준비 ~ 11 L의 BU 1 부 산화 세륨 연마 슬러리 ~ 9 부 탈 이온수 (DI) 물cket). 보메 플로트를 사용하여 보메을 확인합니다. 9.5의 pH를 조정하고 ~ 독점적 ​​인 계면 활성제 (19)의 120 ㎖ (1 부피 %)를 추가 할 수 KOH (10 M)의 ~ 5 ML을 추가합니다. pH와 바움 연마의 모든 24 시간을 조정합니다. </li><li> 여과 시스템으로 제조 된 슬러리 양동이를 설치합니다. 이어서 여과 시스템에 원하는 CMP 입자 필터를 설치한다. 몇 시간 동안 여과 시스템 내에서 슬러리 재순환을 보자. </li><li> 슬러리의 측정 입도 분포 (예를 들어, 하나의 입자 광 센싱 기술을 사용하여) 분포의 꼬리 단부를 충분히 확보하기 위해서는 불량 무 입자 9,20이다. </li></ol> 워크 (에칭 및 차단) 2. 준비 연마 전에, 화학적 손상 21 연삭 서브 표면을 제거하는데 필요한 물질 제거의 양을 줄이기 위해 수용된대로 미세 접지 공작물을 에칭. 종횡비 (즉, 길이 / 두께)&gt; 1 인 경우, (공작물 블록0) (22)를 차단 및 연마 동안 공작물 구부러짐을 방지하는 신규 한 피치 차단 버튼 (PBB) 기술을 사용. <ol><li> NH 4 F : 6 시간 (6 : (BOE) 3X는 DI 물에 희석 한 완충 산화물 에칭)을 제거하는 미세 접지 편 (구체적으로는 265 X 265 X 8mm 3 용융 실리카 유리 평면) HF로 채워진 탱크에 에칭 공작물의 표면에서 유리의 10 μm의. 주의! BOE는 매우 위험합니다; 적절한 개인 보호 장비 (PPE)를 착용. 에칭 탱크에서 작업 물을 제거하고 적극적으로 DI 워터 워크를 씻어 공기 워크 수직으로 건조 할 수 있습니다. </li><li> 어두운 방에 밝은 빛 검사를 사용하여 연마 과정에서 깊은 손상 워크를 검사합니다. 더 깊은 손상이 발견되지 않는 경우, 다른 재 연삭 다시 워크를 보내, 다음 단계로 진행하십시오. </li><li> 아교 총에 피치를 차단 가열의 얼굴에 피치 ~ 95 ºC과 장소 방울 (또한 버튼) (~ 0.06 g)에9 X 9 배열의 차단 판 (26mm 간격으로 81 버튼). 다른 크기의 워크의 경우, 이상적인 수, 크기에 대한 규칙 및 피치 버튼 (22)의 간격을 디자인을 참조하십시오. 적용 버튼을 70 예열 오븐에 얼굴을 차단 플레이트를 배치 ºC. </li><li> 폴리싱 될하지 않은 공작물의면에 테이프를 적용한다. 기포를 생성하거나 과도하게 테이프를 연신 피한다. </li><li> 오븐에 차단 판에 버튼에 내려 테이프 측면과 공작물을 놓습니다. 대류 흐름을 최소화하기 위해 공작물 버튼 블록을 커버. 1.5 시간 후, 실온으로 10 ºC / 시간을 냉각 오븐 설정합니다. 냉각 후, 차단 된 공작물의 피치 두께는 ~ 1mm이어야한다. </li></ol> 3. 집중적 인 연마 <ol><li> 연마 동안 건조에서 슬러리를 방지하기 위해 CISR 광택제의 환경 챔버에서 습도 시스템의 전원을 켜고 워크를 긁적 불량 입자를 최소화 할 수 있습니다. </li><li> INS키와 폴리 셔로 설계하고 준비 격막을 탑재합니다. 워크를 개최 CISR 광택제 낮은 붐에 PBB 공작물을 설치합니다. </li><li> ~ 75mm의 반경 획 1 갤런 / 분의 여과 시스템에서 슬러리 흐름 25 rpm으로 유사한 무릎 공작물 회전 속도로 4 시간 동안 CISR 폴란드어 공작물. 주 : 0.6 psi의 압력을인가하도록 공작물 적재 중량으로 대응하는 차단 판 역할도. </li><li> 무릎과 공작물 회전 및 슬러리의 흐름을 끕니다. CISR 폴리 셔에서 PBB 공작물을 제거하고 DI 물이 채워진 욕조에 그것을 물속에 가라 앉히다. 잠수하는 동안 클린 룸 천으로 공작물 표면을 닦으십시오. DI의 물로 씻어 목욕 PBB 공작물을 제거하고 스프레이. </li><li> 공작물 블록 계면 심을 삽입하여 디 블록 공작물. 공작물 표면에서 테이프를 제거합니다. 적극적으로 DI 물과 공기 건조와 워크를 씻어. </li><li> PBB이어서 PO 반복 항에서 기술 한 공작물의 대향면3 항에 명시된 절차를 퍼블리싱. </li></ol> 4. 계측 및 검사 <ol><li> 측정은, 간섭계를 이용하여 공작물의 양면의 파면 (즉, 표면도)뿐만 아니라 투과 파면을 반영. </li><li> 마운트 밝은 빛 검사 역에 소재 및 광 제조 표준 방법을 사용하여 스크래치 / 발굴 특성을 측정한다. 단계 2.1에 기재된 바와 같이 공작물의 짧은 에칭 BOE는 높은 플루 언스의 레이저 용도에 사용 공작물 숨겨져 흠집을 노출시킬 수있다. 공작물에 미세한 흠집이나 거칠기의 측정을 위해 표준 광학 현미경 또는 백색광 간섭계가 사용될 수있다. </li><li> 스토어 공작물의 얼굴을 가진 컨테이너 최소화 접촉 워크를 완료했다. </li></ol>

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The authors have nothing to disclose.

서론에서 언급 한 바와 같이 제거하거나 인해 워크 형상에 공작물 무릎 불일치의 것을 제외하고 공간 자료 비 균일 영향을 미치는 모든 현상을 최소화 포함, 융합의 성공적인 구현은 그림 표면에 대해 연마. 이러한 현상 중 어느 하나를 적절하게, 어느 공정 제어를 통하여 또는 광택제, 다음 원하는 수렴 점 달성 또는 유지 될 수없는 적절한 공학을 통해 완화되지 않는 경우; 따라서 기본적으로 모?...

일반적인 광 제조 공정의 주요 단계는 성형, 연마, 전체 조리개 연마, 1-3을 연마 때로는 작은 도구를 포함한다. 이미징 및 레이저 시스템을위한 고품질의 광학 부품에 대한 수요 증가, 지난 몇 년 동안 광학 제조에 상당한 발전이 있었다. 예를 들어, 정밀를 들어, 결정 물질 제거 (CNC) 유리 형성 기계 제어 컴퓨터 수치의 발전과 형성 및 연마 과정에서 지금 가능하다. 마찬가지로, 작은 도구 연마 기술 (예를 들어, 컴퓨터 제어 광학 표면 처리 (CCOS), 이온 파악하고, 자기 유동 학적 마무리 (MRF))은 이렇게 강하게 광 제조 산업에 영향을 미치는 결정적 물질 제거 및 표면 그림 컨트롤을 주도했다. 그러나, 마무리 공정을, 전체 개구 연마의 중간 단계는 아직 통상의 숙련을 필요 opticia, 높은 결정 성 결여NS는, 복수를 수행하는 종종 여러 프로세스 변경 긴, 반복주기를 원하는 표면 그림 1-3을 달성하기 위해. 연마 방법, 공정 변수와 복잡한 화학 및 소재, 무릎 및 슬러리 3-4 사이의 기계적 상호 작용의 많은 수는 도전적인 과학 &#39;예술&#39;에서 광학 연마를 변환하기 위해 만들었습니다. 결정적 전체 조리개 연마를 달성하기 위하여, 연마 율은 잘 이해되어야한다. 역사적으로, 소재 제거율은 널리 사용되는 프레스 식 (5)에 의해 설명 되었으나 <img alt="식 (1)" fo:content-width="1in" fo:src="/files/ftp_upload/51965/51965eqn1.jpg" src="/files/ftp_upload/51965/51965eqn1.jpg" width="100px" /> (1) DH / DT는 평균 두께 제거 속도이고, p는 유전 상수 프리스톤, σ O이다적용된 압력 및 V R을 공작물과 무릎 사이의 평균 상대 속도이다. 모식 시공간 속도 변동 및 압력 차이 포함한 프리스톤 수식 바와 같은 재료 제거 속도에 영향을 미치는 물리적 인 개념을 도시 한 도표 적용된 압력 및 압력 분포 공작물 경험과 마찰 효과 6-8. 특히, 공작물에 의해 경험되는 실제 압력 분포 강하게 공작물의 표면도를 수득 영향 (다른 곳에서 상세히 설명한 6-8) 현상의 수에 의해 지배된다. 또한, 프레스톤 식에서 현미경 및 분자 수준의 효과는 주로 전체적인 재료 제거 속도, 마이크로 거칠기, 심지어 공작물에 스크래치에 영향을 육안 프리스톤 상수 (k 값 P), 접혀있다. 다양한 연구는 설명하기 위해 프레스턴의 모델을 확대<html> 미세한 슬러리 입자 패드 워크 상호 작용 물질 제거 속도와 거칠기 9-16를 설명하기 위해. 전체 조리개 폴리싱 동안에도 표면의 결정 성 제어를 달성하기 위해, 상술 한 현상을 각각 정량 이해하고 제어 할 필요가있다. 집중적 인 연마 뒤에 전략 중 설계 광택제 설계를 통해 또는 제거 인해 공작물 형상 공작물 랩 불일치에 의해서만 구동되도록 프로세스 제어에 의해, 제거 또는 비 균일 한 물질 제거의 바람직하지 않은 원인을 최소화하는 것이다 7,17- 18. 그림 2는 공작물 형상이 공작물 무릎 불일치 개념을 기반으로 융합으로 이어질 수있는 방법을 보여줍니다. 평면 무릎과 좌측 상단에 복잡한 모양의 가상 워크를 고려한다. (갭, ΔH 올 라 칭함) 인터페이스 높이 불일치는 인터페이스 압력 분포 (σ)에 영향을 미친다 : 콘텐츠 &quot;FO : 유지-together.within 페이지 =&quot;항상 &quot;&gt; <img alt="식 (2)" fo:content-width="1in" fo:src="/files/ftp_upload/51965/51965eqn2.jpg" src="/files/ftp_upload/51965/51965eqn2.jpg" width="100px" /> (2) h는 상수 설명 속도가 어디되는 압력은 갭 ΔH 올 6의 증가와 함께 감소한다. 이 예에서, 공작물은 폴리싱 동안 높은 초기 물질 제거율을 관찰한다 중심에서 가장 높은 로컬 압력 (도 2의 왼쪽 아래 참조), 따라서이 위치를 갖는다. 재료가 제거 될 때, 공작물에 걸쳐 압력 차이가 공작물 무릎 불일치 감소로 인하여 감소되며, 공작물의 랩 형상으로 수렴된다. 수렴, 공작물 압력 분포, 따라서 물질 제거시 (도 2의 우측 참조)에 걸쳐 균일 한 공작물 것이다. 이 예제는 howev, 평면 무릎에 대한 설명된다어, 동일한 개념은 (오목 또는 볼록 중) 구형 무릎에 적용됩니다. 공간 재료 불균일성에 영향을주는 모든 다른 현상이 제거 된 경우에는 다시,이 수렴 프로세스는 작동한다. 수렴 연마 프로토콜 구현의 구체적인 절차 및 엔지니어링 완화는 토론에 설명되어 있습니다. 다음 연구에 기재된 프로토콜은 미세 지표면에서 시작 26.5 cm 정사각형 용융 실리카 유리 편 특별히 수렴 연마 공정이다. 연마 8 시간 (4 시간 /면),이 소재는 매우 높은 표면 품질 (즉, 낮은 스크래치 밀도)와 함께 ~ λ / 2의 광택 평탄도를 달성 할 수있다.

<table border="0" cellpadding="0" cellspacing="0" width="634">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:251px;">Name of Material/Equipment</td>
			<td style="width:245px;">Company</td>
			<td style="width:139px;">Catalog Number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MHN 50 mil Polyurethane Pad&#160;</td>
			<td>Eminess Technologies</td>
			<td>PF-MHN15A050L-56</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cerium oxide polishing slurry</td>
			<td>Universal Photonics</td>
			<td>HASTILITE PO</td>
		</tr>
		<tr height="21">
			<td dir="LTR" height="21" style="height:21px;width:251px;">Septum Glass (waterjet cut)</td>
			<td dir="LTR" style="width:245px;">Borofloat ; Schott&#160;</td>
			<td dir="LTR" style="width:139px;">NA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Diamond conditioner</td>
			<td>Morgan Advanced Ceramics&#160;</td>
			<td>CMP-25035-SFT</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ultrasonic Cleaner</td>
			<td>Advanced Sonics Processing System</td>
			<td>URC4</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Purification Optima Filter cartridge</td>
			<td>3M</td>
			<td>CMP560P10FC</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Blocking Pitch</td>
			<td>Universal Photonics</td>
			<td>BP1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Blocking Tape</td>
			<td>3M</td>
			<td>#4712</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cleanroom Cloth</td>
			<td>ITW Texwipe</td>
			<td>AlphaWipe TX1013</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Single Particle Optical Sensing</td>
			<td>Paritcle Sizing Systems</td>
			<td>Accusizer 780 AD</td>
		</tr>
	</tbody>
</table>

convergent polishing: a simple, rapid, full aperture polishing process of high quality optical flats &amp; spheres

집중적 인 연마는 초기 형태의 독립적 인 워크, (즉, 표면 그림), 고정, 변하지 않는 조건에서 우수한 표면 품질과 최종 표면의 그림을 수렴 할에 평면과 구면 유리 광학 마무리를위한 새로운 연마 시스템 및 방법입니다 하나의 연마 반복에서 매개 변수를 연마. 대조적으로, 종래의 전체 개구 연마 방법은 원하는 표면도를 달성하는 연마, 계측 및 공정 변화를 포함하는 다수의, 종종 긴 반복주기를 요구한다. 수렴 폴리싱 처리는 무릎의 형태로 수렴 공작물의 제거 및 감소의 결과로 압력 차가 발생 공작물 랩 높이 불일치의 개념에 기초한다. 수렴 폴리싱 공정의 성공적인 구현은 공작물 무릎 제외 불균일 공간 재료 제거 (모두를 제거하기위한 다양한 기술의 조합의 결과이다표면도 컨버전스 불일치) 및 낮은 스크래치 밀도 및 낮은 거칠기 시스템에서 악성 입자의 수​​를 감소시킨다. 수렴 폴리싱 처리는 각종 유리 재료에 모두 아파트와 다양한 형상, 크기의 분야, 및 종횡비의 제조를 위해 설명되었다. 실질적인 영향은 고품질 광학 부품은 낮은 단가의 결과, 이하와 메트 롤로 지, 덜 노동, 더 반복하여,보다 신속하게 제조 될 수 있다는 것이다. 본 연구에서는 융합 연마 프로토콜은 특히 사각 81cm 직경 폴리 셔에 표면 당 4 시간을 연마 한 후 폴리싱 ~ λ / 2면 그림을 잘 접지면에서 실리카 아파트를 융합 26.5 cm 제조 기술되어있다.

집중적 인 연마 프로토콜 상술의 산곡 평탄성, 표면 당 4 시간의 단일 반복에서, 연마 (이 경우 26.5 cm 정사각형)을 접지 용융 실리카 공작물을 허용 ~ λ / 2 (~ 낮은 종횡비의 공작물과 높은 종횡비 가공품 1λ ~ (~ 633 ㎚) 330 ㎚) ()도 3 참조. 다시 한번,이 프로세스는 반복적으로 연마 매개 변수를 변경하지 않고 동일한 최종 표면 도표에 공작물을 집광하고, 초기 표면도 무관하다. 또한, ~ 4?...

Watch this Scientific Journal Video about Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats & Spheres at JoVE.com

Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats &amp; Spheres

A novel optical polishing process, called &#8220;Convergent Polishing&#8221;, which enables faster, lower cost polishing, is described. Unlike conventional polishing processes, Convergent Polishing allows a glass workpiece to be polished in a single iteration and with high surface quality to its final surface figure without requiring changes to polishing parameters.

집중적 인 연마 : 고품질 광학 플랫 &amp; 분야의 단순, 신속, 전체 조리개 연마 공정

Convergent Polishing is a novel polishing system and method for finishing flat and spherical glass optics in which a workpiece, independent of its initial ...

convergent-polishing-simple-rapid-full-aperture-polishing-process

Research

JoVE Journal

Engineering

11.0K 조회수.  Lawrence Livermore National Laboratory. A novel optical polishing process, called “Convergent Polishing”, which enables faster, lower cost polishing, is described. Unlike conventional polishing processes, Convergent Polishing allows a glass workpiece to be polished in a single iteration and with high surface quality to its final surface figure without requiring changes to polishing parameters.

비디오: Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats & Spheres

Fabrication of Silica Ultra High Quality Factor Microresonators

Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the quality factor (Q) of the cavity, can be in excess of 500ns for cavities with Q factors above 100 million. As a result of their low material losses, silica microcavities have demonstrated some of the longest photon lifetimes to date1-2. Since a portion of the circulating light extends outside the resonator, these devices can also be used to probe the surroundings. This interaction has enabled numerous experiments in biology, such as single molecule biodetection and antibody-antigen kinetics, as well as discoveries in other fields, such as development of ultra-low-threshold microlasers, characterization of thin films, and cavity quantum electrodynamics studies.3-7
The two primary silica resonant cavity geometries are the microsphere and the microtoroid. Both devices rely on a carbon dioxide laser reflow step to achieve their ultra-high-Q factors (Q&gt;100 million).1-2,8-9 However, there are several notable differences between the two structures. Silica microspheres are free-standing, supported by a single optical fiber, whereas silica microtoroids can be fabricated on a silicon wafer in large arrays using a combination of lithography and etching steps. These differences influence which device is optimal for a given experiment.
Here, we present detailed fabrication protocols for both types of resonant cavities. While the fabrication of microsphere resonant cavities is fairly straightforward, the fabrication of microtoroid resonant cavities requires additional specialized equipment and facilities (cleanroom). Therefore, this additional requirement may also influence which device is selected for a given experiment.
Introduction
An optical resonator efficiently confines light at specific wavelengths, known as the resonant wavelengths of the device. 1-2 The common figure of merit for these optical resonators is the quality factor or Q. This term describes the photon lifetime (&tau;o) within the resonator, which is directly related to the resonator's optical losses. Therefore, an optical resonator with a high Q factor has low optical losses, long photon lifetimes, and very low photon decay rates (1/&tau;o). As a result of the long photon lifetimes, it is possible to build-up extremely large circulating optical field intensities in these devices. This very unique property has allowed these devices to be used as laser sources and integrated biosensors.10
A unique sub-class of resonators is the whispering gallery mode optical microcavity. In these devices, the light is confined in circular orbits at the periphery. Therefore, the field is not completely confined within the device, but evanesces into the environment. Whispering gallery mode optical cavities have demonstrated some of the highest quality factors of any optical resonant cavity to date.9,11 Therefore, these devices are used throughout science and engineering, including in fundamental physics studies and in telecommunications as well as in biodetection experiments. 3-7,12
Optical microcavities can be fabricated from a wide range of materials and in a wide variety of geometries. A few examples include silica and silicon microtoroids, silicon, silicon nitride, and silica microdisks, micropillars, and silica and polymer microrings.13-17 The range in quality factor (Q) varies as dramatically as the geometry. Although both geometry and high Q are important considerations in any field, in many applications, there is far greater leverage in boosting device performance through Q enhancement. Among the numerous options detailed previously, the silica microsphere and the silica microtoroid resonator have achieved some of the highest Q factors to date.1,9 Additionally, as a result of the extremely low optical loss of silica from the visible through the near-IR, both microspheres and microtoroids are able to maintain their Q factors over a wide range of testing wavelengths.18 Finally, because silica is inherently biocompatible, it is routinely used in biodetection experiments.
In addition to high material absorption, there are several other potential loss mechanisms, including surface roughness, radiation loss, and contamination loss.2 Through an optimization of the device size, it is possible to eliminate radiation losses, which arise from poor optical field confinement within the device. Similarly, by storing a device in an appropriately clean environment, contamination of the surface can be minimized. Therefore, in addition to material loss, surface scattering is the primary loss mechanism of concern.2,8
In silica devices, surface scattering is minimized by using a laser reflow technique, which melts the silica through surface tension induced reflow. While spherical optical resonators have been studied for many years, it is only with recent advances in fabrication technologies that researchers been able to fabricate high quality silica optical toroidal microresonators (Q&gt;100 million) on a silicon substrate, thus paving the way for integration with microfluidics.1
The present series of protocols details how to fabricate both silica microsphere and microtoroid resonant cavities. While silica microsphere resonant cavities are well-established, microtoroid resonant cavities were only recently invented.1 As many of the fundamental methods used to fabricate the microsphere are also used in the more complex microtoroid fabrication procedure, by including both in a single protocol it will enable researchers to more easily trouble-shoot their experiments.

We describe the use of a carbon dioxide laser reflow technique to fabricate silica resonant cavities, including free-standing microspheres and on-chip microtoroids. The reflow method removes surface imperfections, allowing long photon lifetimes within both devices. The resulting devices have ultra high quality factors, enabling applications ranging from telecommunications to biodetection.

실리카 초고 품질 팩터 Microresonators의 제작

Whispering gallery resonant cavities confine light in circular orbits at their periphery.1-2 The photon storage lifetime in the cavity, quantified by the ...

연구

공학

Process of Making Three-dimensional Microstructures using Vaporization of a Sacrificial Component

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material fabrication techniques are able to mimic the complexity of these structures while maintaining scalability. The Vaporization of a Sacrificial Component (VaSC) process is able to do so. This process uses sacrificial fibers as a template to form hollow, cylindrical microchannels embedded within a matrix. Tin (II) oxalate (SnOx) is embedded within poly(lactic) acid (PLA) fibers which facilitates the use of this process. The SnOx catalyzes the depolymerization of the PLA fibers at lower temperatures. The lactic acid monomers are gaseous at these temperatures and can be removed from the embedded matrix at temperatures that do not damage the matrix. Here we show a method for aligning these fibers using micromachined plates and a tensioning device to create complex patterns of three-dimensionally arrayed microchannels. The process allows the exploration of virtually any arrangement of fiber topologies and structures.

The Vaporization of a Sacrificial Component (VaSC) process is used to fabricate microvascular structures. This procedure uses sacrificial poly(lactic) acid fibers to form hollow microchannels with precise 3D geometric positioning provided by laser micromachined guide plates.

희생 구성 요소의 증발을 사용하여 세 가지 차원 미세 만들기의 과정

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material ...

Construction of a High Resolution Microscope with Conventional and Holographic Optical Trapping Capabilities

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular organelles 2,3, as well as for high spatial and temporal resolution readout of their position relative to the center of the trap. The system described herein has one such "traditional" trap operating at 980 nm. It additionally provides a second optical trapping system that uses a commercially available holographic package to simultaneously create and manipulate complex trapping patterns in the field of view of the microscope 4,5 at a wavelength of 1,064 nm. The combination of the two systems allows for the manipulation of multiple refractive objects at the same time while simultaneously conducting high speed and high resolution measurements of motion and force production at nanometer and piconewton scale.

The system described herein employs a traditional optical trap as well as an independent holographic optical trapping line, capable of creating and manipulating multiple traps. This allows for the creation of complex geometric arrangements of refractive particles while also permitting simultaneous high-speed, high-resolution measurements of the activity of biological enzymes.

기존 및 홀로 그래픽 광학 트래핑 기능과 고해상도 현미경의 구조

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular ...

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light.
We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry.

Large laser-interferometers are being constructed to create a new type of astronomy based on gravitational waves. Their sensitivities, as for many other high-precision experiments, are approaching fundamental noise limits such as the atomic vibration of their components. We are pioneering technologies to overcome these limits using novel laser beam shapes.

고정밀 간섭에 대한 높은 순서 Laguerre-가우스 광학 빔의 생성

Thermal noise in high-reflectivity mirrors is a major impediment for several  types of high-precision interferometric experiments that aim to reach the  ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

실리콘 엘라스토머 계 유전 액츄에이터 제조 공정

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Adsorption Device Based on a Langatate Crystal Microbalance for High Temperature High Pressure Gas Adsorption in Zeolite H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate crystal microbalance, LCM) and its use for gas adsorption measurements in zeolite H-ZSM-5. Prior to the adsorption measurements, zeolite H-ZSM-5 crystals were synthesized on the gold electrode in the center of the LCM, without covering the connection points of the gold electrodes to the oscillator, by the steam-assisted crystallization (SAC) method, so that the zeolite crystals remain attached to the oscillating microbalance while keeping good electroconductivity of the LCM during the adsorption measurements. Compared to a conventional quartz crystal microbalance (QCM) which is limited to temperatures below 80 &#176;C, the LCM can realize the adsorption measurements in principle at temperatures as high as 200-300 &#176;C (i.e., at or close to the reaction temperature of the target application of one-stage DME synthesis from the synthesis gas), owing to the absence of crystalline-phase transitions up to its melting point (1,470 &#176;C). The system was applied to investigate the adsorption of CO2, H2O, methanol and dimethyl ether (DME), each in the gas phase, on zeolite H-ZSM-5 in the temperature and pressure range of 50-150 &#176;C and 0-18 bar, respectively. The results showed that the adsorption isotherms of these gases in H-ZSM-5 can be well fitted by Langmuir-type adsorption isotherms. Furthermore, the determined adsorption parameters, i.e., adsorption capacities, adsorption enthalpies, and adsorption entropies, compare well to literature data. In this work, the results for CO2 are shown as an example.

A protocol for high-temperature and high-pressure gas adsorption measurements on zeolite H-ZSM-5 using an adsorption measurement device based on a langatate crystal microbalance is presented. Prior to the adsorption measurements, the synthesis of zeolite H-ZSM-5 on the langatate crystal microbalance sensor by the steam-assisted crystallization (SAC) method is demonstrated.

제올라이트 고온 고압의 가스 흡착 용 Langatate 크리스탈 마이크로 밸런스 기준 흡착 기기 H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

Challenges in Rheological Characterization of Highly Concentrated Suspensions &amp;#8212; A Case Study for Screen-printing Silver Pastes

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

고농도 현탁액의 유변학 적 특성에 도전 - 스크린 인쇄 실버 페이스트에 대한 사례 연구

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...

Method for Recording Broadband High Resolution Emission Spectra of Laboratory Lightning Arcs

Lightning is one of the most common and destructive forces in nature and has long been studied using spectroscopic techniques, first with traditional camera film methods and then digital camera technology, from which several important characteristics have been derived. However, such work has always been limited due to the inherently random and non-repeatable nature of natural lightning events in the field. Recent developments in lightning test facilities now allow the reproducible generation of lightning arcs within controlled laboratory environments, providing a test bed for the development of new sensors and diagnostic techniques to understand lightning mechanisms better. One such technique is a spectroscopic system using digital camera technology capable of identifying the chemical elements with which the lightning arc interacts, with these data then being used to derive further characteristics. In this paper, the spectroscopic system is used to obtain the emission spectrum from a 100 kA peak, 100 &#181;s duration lightning arc generated across a pair of hemispherical tungsten electrodes separated by a small air gap. To maintain a spectral resolution of less than 1 nm, several individual spectra were recorded across discrete wavelength ranges, averaged, stitched, and corrected to produce a final composite spectrum in the 450 nm (blue light) to 890 nm (near infrared light) range. Characteristic peaks within the data were then compared to an established publicly available database to identify the chemical element interactions. This method is readily applicable to a variety of other light emitting events, such as fast electrical discharges, partial discharges, and sparking in electrical equipment, apparatus, and systems.

Emission spectroscopy techniques have traditionally been used to analyze inherently random lightning arcs occurring in nature. In this paper, a method developed to obtain the emission spectroscopy from reproducible lightning arcs generated within a laboratory environment is described.

실험실 번개 아크의 광대역 고분해능 방출 스펙트럼을 기록하는 방법

Lightning is one of the most common and destructive forces in nature and has long been studied using spectroscopic techniques, first with traditional ...

Atomic Layer Deposition of Vanadium Dioxide and a Temperature-dependent Optical Model

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with wafer-scale uniformity and angstrom level control of thickness, the method of atomic-layer deposition was chosen. This ALD process enables high-quality, low-temperature (&#8804;150 &#176;C) growth of ultrathin films (100-1000 &#197;) of VO2. For this demonstration, the VO2 films were grown on sapphire substrates. This low temperature growth technique produces mostly amorphous VO2 films. A subsequent anneal in an ultra-high vacuum chamber with a pressure of 7x10-4 Pa of ultra-high purity (99.999%) oxygen produced oriented, polycrystalline VO2 films. The crystallinity, phase, and strain of the VO2 were determined by Raman spectroscopy and X-ray diffraction, while the stoichiometry and impurity levels were determined by X-ray photoelectron spectroscopy, and finally the morphology was determined by atomic force microscopy. These data demonstrate the high-quality of the films grown by this technique. A model was created to fit to the data for VO2 in its metallic and insulating phases in the near infrared spectral region. The permittivity and refractive index of the ALD VO2 agreed well with the other fabrication methods in its insulating phase, but showed a difference in its metallic state. Finally, the analysis of the films&#39; optical properties enabled the creation of a wavelength- and temperature-dependent model of the complex optical refractive index for developing VO2 as a tunable refractive index material.

Thin films (100-1000 &#197;) of vanadium dioxide (VO2) were created by atomic-layer deposition (ALD) on sapphire substrates. Following this, the optical properties were characterized through the metal-insulator transition of VO2. From the measured optical properties, a model was created to describe the tunable refractive index of VO2.

바나듐이 산화물 및 온도 따른 광 모델의 원자 층 증 착

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with ...

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a fixed bed are important phenomena in catalyst technology. The mechanical strength of the catalyst is measured here by its bending strength or flexural strength. This technique is relatively new from the perspective of applying it to commercial catalysts of typical sizes used in the industry. Catalyst breakage by collision against a surface is measured after a fall of the extrudates through the ambient air in a vertical pipe. Quantifying the impact force is done theoretically by applying Newton's second law. Measurement of catalyst breakage due to stress in a fixed bed is done following the standard procedure of the bulk crush strength test. Novel here is the focus on measuring the reduction in the length to diameter ratio of the extrudates as a function of the stress.

Here we present a protocol to measure the modulus of rupture of an extruded catalyst and the breakage of said catalyst extrudates by collision against a surface or by compression in a fixed bed.

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a ...