The authors gratefully acknowledge Dr Matteo Galli, Dr Simone L. Portalupi and Prof. Lucio C. Andreani from the University of Pavia for helpful discussions related to the RS technique and the execution of measurements.

Disclaimer: The following protocol gives a general process flow covering the fabrication and characterization techniques for photonic crystal waveguides and cavities. The process flow is optimized for the specific equipment available in our laboratory, and parameters may differ if other reagents or equipment is used.
1. Sample Preparation
<ol>
	<li>Sample Cleaving - take the silicon-on-insulator (SOI) wafer and use a diamond scribe to scratch a line approximately 1-2 mm long...

<ol>
	<li>Baba, T., Kawasaki, T., Sasaki, H., Adachi, J., Mori, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+delay-bandwidth+product+and+tuning+of+slow+light+pulse+in+photonic+crystal+coupled+waveguide.">Large delay-bandwidth product and tuning of slow light pulse in photonic crystal coupled waveguide.</a> Opt. Express. 16 (12), 9245-9253 (2008).</li><li>Melloni, A., Canciamilla, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tunable+delay+lines+in+silicon+photonics:+coupled+resonators+and+photonic+crystals,+a+comparison.">Tunable delay lines in silicon photonics: coupled resonators and photonic crystals, a comparison.</a> IEEE Photon. J. 2 (2), 181-194 (2010).</li><li>Ishikura, N., Baba, T., Kuramochi, E., Notomi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+tunable+fractional+delay+of+slow+light+pulse+and+its+application+to+fast+optical+correlator.">Large tunable fractional delay of slow light pulse and its application to fast optical correlator.</a> Opt. Express. 19 (24), 24102-24108 (2011).</li><li>Beggs, D. M., Rey, I. H., Kampfrath, T., Rotenberg, N., Kuipers, L., Krauss, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrafast+tunable+optical+delay+line+based+on+indirect+photonic+transitions.">Ultrafast tunable optical delay line based on indirect photonic transitions.</a> Phys. Rev. Lett. 108 (21), 213901 (2012).</li><li>Beggs, D. M., White, T. P., O'Faolain, L., Krauss, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultracompact+and+low-power+optical+switch+based+on+silicon+photonic+crystals.">Ultracompact and low-power optical switch based on silicon photonic crystals.</a> Opt. Lett. 33 (2), 147-149 (2008).</li><li>Nguyen, H. C., Sakai, Y., Shinkawa, M., Ishikura, N., Baba, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=10+Gb/s+operation+of+photonic+crystal+silicon+optical+modulators.">10 Gb/s operation of photonic crystal silicon optical modulators.</a> Opt. Express. 19 (14), 13000-13007 (1364).</li><li>Kampfrath, T., Beggs, D. M., White, T. P., Melloni, A., Krauss, T. F., Kuipers, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrafast+adiabatic+manipulation+of+slow+light+in+a+photonic+crystal.">Ultrafast adiabatic manipulation of slow light in a photonic crystal.</a> Phys. Rev. A. 81 (4), 043837 (2010).</li><li>Monat, C., Corcoran, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Slow+light+enhancement+of+nonlinear+effects+in+silicon+engineered+photonic+crystal+waveguides.">Slow light enhancement of nonlinear effects in silicon engineered photonic crystal waveguides.</a> Opt. Express. 17 (4), 2944-2953 (2009).</li><li>Corcoran, B., Monat, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=light+emission+in+silicon+through+slow-light+enhanced+third-harmonic+generation+in+photonic-crystal+waveguides.">light emission in silicon through slow-light enhanced third-harmonic generation in photonic-crystal waveguides.</a> Nature Photon. 3, 206-210 (2009).</li><li>Li, J., O'Faolain, L., Rey, I. H., Krauss, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Four-wave+mixing+in+photonic+crystal+waveguides:+slow+light+enhancement+and+limitations.">Four-wave mixing in photonic crystal waveguides: slow light enhancement and limitations.</a> Opt. Express. 19 (5), 4458-4463 (2010).</li><li>Checoury, X., Han, Z., Boucaud, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimulated+Raman+scattering+in+silicon+photonic+crystal+waveguides+under+continuous+excitation.">Stimulated Raman scattering in silicon photonic crystal waveguides under continuous excitation.</a> Phys. Rev. B. 82 (4), 041308 (2010).</li><li>Y, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photonic+crystal+nanocavity+laser+with+a+single+quantum+dot+gain.">Photonic crystal nanocavity laser with a single quantum dot gain.</a> Opt. Express. 17 (18), 15975-15982 (2009).</li><li>Ellis, B., Mayer, M. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultralow-threshold+electrically+pumped+quantum-dot+photonic-crystal+nanocavity+laser.">Ultralow-threshold electrically pumped quantum-dot photonic-crystal nanocavity laser.</a> Nature Photon. 24, 297-300 (2011).</li><li>Galli, M., Gerace, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-power+continuous-wave+generation+of+visible+harmonics+in+silicon+photonic+crystal+nanocavities.">Low-power continuous-wave generation of visible harmonics in silicon photonic crystal nanocavities.</a> Opt. Express. 18 (25), 26613-26624 (2010).</li><li>Notomi, M., Shinya, A., Mitsugi, S., Kira, G., Kuramochi, E., Tanabe, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+bistable+switching+action+of+Si+high-Q+photonic-crystal+nanocavities.">Optical bistable switching action of Si high-Q photonic-crystal nanocavities.</a> Opt. Express. 13 (7), 2678-2687 (2005).</li><li>Shambat, G., Rivoire, K., Lu, J., Hatami, F., Vu&#269;kovi&#269;, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tunable-wavelength+second+harmonic+generation+from+GaP+photonic+crystal+cavities+coupled+to+fiber+tapers.">Tunable-wavelength second harmonic generation from GaP photonic crystal cavities coupled to fiber tapers.</a> Opt. Express. 18 (12), 12176-12184 (2010).</li><li>Fan, S., Villeneuve, P. R., Joannopoulos, J. D., Haus, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Channel+drop+filters+in+photonic+crystals.">Channel drop filters in photonic crystals.</a> Opt. Express. 3 (1), 4-11 (1998).</li><li>Tanabe, T., Nishiguchi, K., Kuramochi, E., Notomi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+power+and+fast+electro-optic+silicon+modulator+with+lateral+p-i-n+embedded+photonic+crystal+nanocavity.">Low power and fast electro-optic silicon modulator with lateral p-i-n embedded photonic crystal nanocavity.</a> Opt. Express. 17 (25), 22505-22513 (2009).</li><li>Nozaki, K., Tanabe, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sub-femtojoule+all-optical+switching+using+a+photonic-crystal+nanocavity.">Sub-femtojoule all-optical switching using a photonic-crystal nanocavity.</a> Nature Photon. 4, 477-483 (2010).</li><li>Notomi, M., Yamada, K., Shinya, A., Takahashi, J., Takahashi, C., Yokohama, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extremely+large+group-velocity+dispersion+of+line-defect+waveguides+in+photonic+crystal+slabs.">Extremely large group-velocity dispersion of line-defect waveguides in photonic crystal slabs.</a> Phys. Rev. Lett. 87 (25), 253902 (2001).</li><li>Labilloy, D., Benisty, H., Weisbuch, C., Smith, C. J. M., Krauss, T. F., Houdr&#233;, R., Oesterle, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Finely+resolved+transmission+spectra+and+band+structure+of+two-dimensional+photonic+crystals+using+emission+from+InAs+quantum+dots.">Finely resolved transmission spectra and band structure of two-dimensional photonic crystals using emission from InAs quantum dots.</a> Phys. Rev. B. 59 (3), 1649-1652 (1999).</li><li>Inan&#231; Tarhan, I., Zinkin, M. P., Watson, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interferometric+technique+for+the+measurement+of+photonic+band+structure+in+colloidal+crystals.">Interferometric technique for the measurement of photonic band structure in colloidal crystals.</a> Opt. Lett. 20 (14), 1571-1573 (1995).</li><li>Galli, M., Marabelli, F., Guizzetti, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+measurement+of+refractive-index+dispersion+of+transparent+media+by+white-light+interferometry.">Direct measurement of refractive-index dispersion of transparent media by white-light interferometry.</a> Appl. Opt. 42 (19), 3910-3914 (1364).</li><li>Galli, M., Bajoni, D., Marabelli, F., Andreani, L. C., Pavesi, L., Pucker, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photonic+bands+and+group-velocity+dispersion+in+Si/SiO2+photonic+crystals+from+white-light+interferometry.">Photonic bands and group-velocity dispersion in Si/SiO2 photonic crystals from white-light interferometry.</a> Phys. Rev. B. 69 (11), 115107 (2004).</li><li>Vlasov, Y. A., O'Boyle, M., Hamann, H. F., McNab, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Active+control+of+slow+light+on+a+chip+with+photonic+crystal+waveguides.">Active control of slow light on a chip with photonic crystal waveguides.</a> Nature. 438, 65-69 (2005).</li><li>Gomez-Iglesias, A., O'Brien, D., O'Faolain, L., Miller, A., Krauss, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+measurement+of+the+group+index+of+photonic+crystal+waveguide+via+Fourier+transform+spectral+interferometry.">Direct measurement of the group index of photonic crystal waveguide via Fourier transform spectral interferometry.</a> Appl. Phys. Lett. 90 (26), 261107 (2007).</li><li>Akahane, Y., Asano, T., Song, B. -. S., Noda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Q+photonic+nanocavity+in+a+two-dimensional+photonic+crystal.">High-Q photonic nanocavity in a two-dimensional photonic crystal.</a> Nature. 425, 944-947 (2003).</li><li>McCutcheon, M. W., Rieger, G. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resonant+scattering+and+second-harmonic+spectroscopy+of+planar+photonic+crystal+microcavities.">Resonant scattering and second-harmonic spectroscopy of planar photonic crystal microcavities.</a> Appl. Phys. Lett. 87 (22), 221110 (2005).</li><li>Galli, M., Portalupi, S. L., Belotti, M., Andreani, L. C., O'Faolain, L., Krauss, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light+scattering+and+Fano+resonances+in+high-Q+photonic+crystal+nanocavities.">Light scattering and Fano resonances in high-Q photonic crystal nanocavities.</a> Appl. Phys. Lett. 94 (7), 71101 (2009).</li><li>W&#195;est, R., Strasser, P., Jungo, M., Robin, F., Erni, D., J&#252;ckel, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+efficient+proximity-effect+correction+method+for+electron-beam+patterning+of+photonic-crystal+devices.">An efficient proximity-effect correction method for electron-beam patterning of photonic-crystal devices.</a> Microelectron Eng. 67-68, 182-188 (2003).</li><li>Tanaka, Y., Asano, T., Akahane, Y., Song, B. -. S., Noda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Theoretical+investigation+of+a+two-dimensional+photonic+crystal+slab+with+truncated+cone+air+holes.">Theoretical investigation of a two-dimensional photonic crystal slab with truncated cone air holes.</a> Appl. Phys. Lett. 82 (11), 1661 (2003).</li><li>Asano, T., Song, B. -. S., Noda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+the+experimental+Q+factors+(~+1+million)+of+photonic+crystal+nanocavities.">Analysis of the experimental Q factors (~ 1 million) of photonic crystal nanocavities.</a> Opt. Express. 14 (5), 1996-2002 (2006).</li><li>O'Faolain, L., Schulz, S. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Loss+engineered+slow+light+waveguides.">Loss engineered slow light waveguides.</a> Opt. Express. 18 (26), 27627-27638 (2010).</li><li>Joannopoulos, J. D., Johnson, S. G., Winn, J. N., Meade, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Photonic crystals, molding the flow of light. , (2008).</li><li>Li, J., White, T. P., O'Faolain, L., Gomez-Iglesias, A., Krauss, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systematic+design+of+flat+band+slow+light+in+photonic+crystal+waveguides.">Systematic design of flat band slow light in photonic crystal waveguides.</a> Opt. Express. 16 (9), 6227-6232 (2008).</li><li>Takeda, M., Ina, H., Kobayashi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fourier-transform+method+of+fringe-pattern+analysis+for+computer-based+topography+and+interferometry.">Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry.</a> J. Opt. Soc. Am. 72 (1), 156-160 (1982).</li></ol>

Sample fabrication
Our choice of electron-beam resist (i.e. ZEP 520A) is due to its simultaneously high resolution and etch resistance. We believe that ZEP 520A may be affected by the UV light emitted from overhead laboratory lights; as such we recommend placing spin-coated samples in UV opaque containers while moving them from one laboratory to another.
Moving onto defining the photonic crystal pattern, before exposing the sample we have found that allowing t...

<table border="1">
	<tbody>
		<tr>
			<td>Name </td>
			<td>Company </td>
			<td>Catalogue number </td>
			<td>Comments (optional) </td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Fisher Scientific</td>
			<td>A/0520/17</td>
			<td>CAUTION: flammable, use good ventilation and avoid all ignition sources.</td>
		</tr>
		<tr>
			<td>Isopropanol</td>
			<td>Fisher Scientific</td>
			<td>P/7500/15</td>
			<td>CAUTION: flammable, use good ventilation and avoid all ignition sources.</td>
		</tr>
		<tr>
			<td>Electron Beam resist</td>
			<td>Marubeni Europe plc.</td>
			<td>ZEP520A</td>
			<td>CAUTION: flammable, harmful by inhalation, avoid contact with skin and eyes.</td>
		</tr>
		<tr>
			<td>Xylene</td>
			<td>Fisher Scientific</td>
			<td>X/0100/17</td>
			<td>CAUTION: flammable and highly toxic, use good ventilation, avoid all ignition sources, avoid contact with skin and eyes.</td>
		</tr>
		<tr>
			<td>Microposit S1818 G2</td>
			<td>Chestech Ltd.</td>
			<td>10277866</td>
			<td>CAUTION: flammable and causes irritation to eyes, nose and respiratory tract.</td>
		</tr>
		<tr>
			<td>Microposit Developer MF-319</td>
			<td>Chestech Ltd.</td>
			<td>10058721</td>
			<td>CAUTION: alkaline liquid and can cause irritation to eyes, nose and respiratory tract.</td>
		</tr>
		<tr>
			<td>Hydrofluoric Acid</td>
			<td>Fisher Scientific</td>
			<td>22333-5000</td>
			<td>CAUTION: extremely corrosive, readily destroys tissue; handle with full personal protective equipment rated for HF.</td>
		</tr>
		<tr>
			<td>Microposit 1165 Remover</td>
			<td>Chestech Ltd.</td>
			<td>10058734</td>
			<td>CAUTION: flammable and causes irritation to eyes, nose and respiratory tract.</td>
		</tr>
		<tr>
			<td>Sulphuric Acid</td>
			<td>Fisher Scientific</td>
			<td>S/9120/PB17</td>
			<td>CAUTION: corrosive and very toxic; handle with personal protective equipment and avoid inhalation of vapours or mists.</td>
		</tr>
		<tr>
			<td>Hydrogen Peroxide</td>
			<td>Fisher Scientific</td>
			<td>BPE2633-500</td>
			<td>CAUTION: very hazardous in case of skin and eye contact; handle with personal protective equipment.</td>
		</tr>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Silicon-on-Insulator wafer</td>
			<td>Soitec</td>
			<td>G8P-110-01</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Diamond Scribe</td>
			<td>J &amp; M Diamond Tool Inc.</td>
			<td>HS-415</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Microscope slides</td>
			<td>Fisher Scientific</td>
			<td>FB58622</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Beakers</td>
			<td>Fisher Scientific</td>
			<td>FB33109</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Tweezers</td>
			<td>SPI Supplies</td>
			<td>PT006-AB</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Ultrasonic Bath</td>
			<td>Camlab</td>
			<td>1161436</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Spin-Coater</td>
			<td>Electronic Micro Systems Ltd.</td>
			<td>EMS 4000</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Pipette</td>
			<td>Fisher Scientific</td>
			<td>FB55343</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>E-beam Lithography System</td>
			<td>Raith Gmbh</td>
			<td>Raith 150</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Reactive Ion Etching System</td>
			<td>Proprietary In-house Designed</td>
			<td>--</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>UV Mask Aligner</td>
			<td>Karl Suss</td>
			<td>MJB-3</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>ASE source</td>
			<td>Amonics</td>
			<td>ALS-CL-15-B-FA</td>
			<td>CAUTION: invisible IR radiation.</td>
		</tr>
		<tr>
			<td>Single mode fibers</td>
			<td>Thorlabs</td>
			<td>P1-SMF28E-FC-2</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>3 dB fiber splitters</td>
			<td>Thorlabs</td>
			<td>C-WD-AL-50-H-2210-35-FC/FC</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Aspheric lenses</td>
			<td>New Focus</td>
			<td>5720-C</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>XYZ stages</td>
			<td>Melles Griot</td>
			<td>17AMB003/MD</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Polarizing beamsplitter cube</td>
			<td>Thorlabs</td>
			<td>PBS104</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>IR detector</td>
			<td>New Focus</td>
			<td>2033</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>100&times; Objective</td>
			<td>Nikon</td>
			<td>BD Plan 100x</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Oscilloscope</td>
			<td>Tektronix</td>
			<td>TDS1001B</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Optical Spectrum Analyzer</td>
			<td>Advantest</td>
			<td>Q8384</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>IR sensor card</td>
			<td>Newport</td>
			<td>F-IRC2</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>TLS source</td>
			<td>Agilent</td>
			<td>81940A</td>
			<td>CAUTION: invisible IR radiation.</td>
		</tr>
		<tr>
			<td>IR Camera</td>
			<td>Electrophysics</td>
			<td>7290A</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>IR Detector</td>
			<td>New Focus</td>
			<td>2153</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Digital Multimeter</td>
			<td>Agilent</td>
			<td>34401A</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Illumination</td>
			<td>Stocker Yale</td>
			<td>Lite Mite</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Monochromator</td>
			<td>Spectral Products</td>
			<td>DK480</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Array Detector</td>
			<td>Andor</td>
			<td>DU490A-1.7</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>GIF Fiber</td>
			<td>Thorlabs</td>
			<td>31L02</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

fabrication and characterization of photonic crystal slow light waveguides and cavities

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view and for its considerable potential for practical applications. Slow light photonic crystal waveguides, in particular, have played a major part and have been successfully employed for delaying optical signals1-4 and the enhancement of both linear5-7 and nonlinear devices.8-11
Photonic crystal cavities achieve similar effects to that of slow light waveguides, but over a reduced band-width. These cavities offer high Q-factor/volume ratio, for the realization of optically12 and electrically13 pumped ultra-low threshold lasers and the enhancement of nonlinear effects.14-16 Furthermore, passive filters17 and modulators18-19 have been demonstrated, exhibiting ultra-narrow line-width, high free-spectral range and record values of low energy consumption.
To attain these exciting results, a robust repeatable fabrication protocol must be developed. In this paper we take an in-depth look at our fabrication protocol which employs electron-beam lithography for the definition of photonic crystal patterns and uses wet and dry etching techniques. Our optimised fabrication recipe results in photonic crystals that do not suffer from vertical asymmetry and exhibit very good edge-wall roughness. We discuss the results of varying the etching parameters and the detrimental effects that they can have on a device, leading to a diagnostic route that can be taken to identify and eliminate similar issues.
The key to evaluating slow light waveguides is the passive characterization of transmission and group index spectra. Various methods have been reported, most notably resolving the Fabry-Perot fringes of the transmission spectrum20-21 and interferometric techniques.22-25 Here, we describe a direct, broadband measurement technique combining spectral interferometry with Fourier transform analysis.26 Our method stands out for its simplicity and power, as we can characterise a bare photonic crystal with access waveguides, without need for on-chip interference components, and the setup only consists of a Mach-Zehnder interferometer, with no need for moving parts and delay scans.
When characterising photonic crystal cavities, techniques involving internal sources21 or external waveguides directly coupled to the cavity27 impact on the performance of the cavity itself, thereby distorting the measurement. Here, we describe a novel and non-intrusive technique that makes use of a cross-polarised probe beam and is known as resonant scattering (RS), where the probe is coupled out-of plane into the cavity through an objective. The technique was first demonstrated by McCutcheon et al.28 and further developed by Galli et al.29

Fabricated samples
Figure 1 shows a scanning electron microscope (SEM) image of an exposed and developed pattern in electron beam resist - it is evident from the "clean" edge between the resist and the silicon substrate that complete exposure/development has been accomplished. Exposure of dose test patterns, consisting of simple repeated shapes (in our case 50 &times; 50 &mu;m squares), each with a differing base dose, are used to determine the correct dose factor and developmen...

Watch this Scientific Journal Video about Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities at JoVE.com

Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities

Use of photonic crystal slow light waveguides and cavities has been widely adopted by the photonics community in many differing applications. Therefore fabrication and characterization of these devices are of great interest. This paper outlines our fabrication technique and two optical characterization methods, namely: interferometric (waveguides) and resonant scattering (cavities).

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view ...

fabrication-characterization-photonic-crystal-slow-light-waveguides

Research

JoVE Journal

Engineering

18.8K vistas.  University of St Andrews. El uso de guías de ondas de luz de cristal fotónico lentos y cavidades ha sido ampliamente adoptado por la comunidad fotónica en muchas aplicaciones diferentes. Por lo tanto la fabricación y caracterización de estos dispositivos son de gran interés. En este trabajo se describe nuestra técnica de fabricación y dos métodos de caracterización óptica, a saber: la dispersión interferométrica (guías de onda) y resonancia (cavidades).