Summary

Изготовление и характеристика фотонного кристалла медленно волноводы Света и полостей

Published: November 30, 2012
doi:

Summary

Использование фотонных кристаллов медленный волноводы света и полости была широко принята сообществом фотоники во многих различных приложениях. Поэтому изготовления и характеристики этих устройств представляют большой интерес. В настоящем документе излагается наша техника изготовления и два оптических методов характеристику, а именно: интерферометрических (волноводы) и резонансное рассеяние (полостей).

Abstract

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

Protocol

Предупреждение: следующий протокол дает общий поток процесса, охватывающего производство и характеристика методов для фотонных кристаллов волноводов и резонаторов. Процесс потока оптимизирована для конкретного оборудования, имеющегося в нашей лаборатории, и параметры мог?…

Representative Results

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 × 50 μm squares), each with a differing base dose, are used to determine the correct dose factor and developmen…

Discussion

Примеры изготовления

Наш выбор электронно-лучевой сопротивление (т.е. ZEP 520A) связано с его одновременно с высоким разрешением и травления сопротивление. Мы считаем, что ZEP 520A могут быть затронуты УФ-света, излучаемого от верхнего освещения лаборатории, как таковой, мы ?…

Declarações

The authors have nothing to disclose.

Acknowledgements

Авторы выражают благодарность д-р Маттео Галли, д-р Симон Л. Portalupi и профессор Лучио C. Andreani из Университета Павии за полезные обсуждения, связанные с техникой RS и выполнения измерений.

Materials

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

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Reardon, C. P., Rey, I. H., Welna, K., O’Faolain, L., Krauss, T. F. Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities. J. Vis. Exp. (69), e50216, doi:10.3791/50216 (2012).

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