| 1. |
- Berrier, Audrey, et al.
(författare)
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Characterization of the feature-size dependence in Ar/Cl2 chemically assisted ion beam etching of InP-based photonic crystal devices
- 2007
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Ingår i: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567. ; 25:1, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- The authors address feature-size dependence in Ar/Cl-2, chemically assisted ion beam etching (CAIBE) in the context of the fabrication of photonic crystal (PhC) structures. They systematically investigate the influence of various parameters such as hole diameter (115-600 nm), etch duration (10-60 min), and ion beam energy (300-600 eV) on PhC etching in InP with Ar/Cl-2, CAIBE. For a 60 min etching at an Ar-ion energy of 400 eV, the authors report an etch depth of 5 mu m for hole diameters d larger than 300 nm; the etch depth is in excess of 3 mu m for d larger than 200 nm. The evolution of roughness at the bottom of the etched holes and its dependence on hole size and etching conditions,is discussed. The physical mechanism of the observed feature-size dependent etching (FSDE) is then discussed and the effect of the process parameters is qualitatively understood using a model combining the effect of ion sputtering and surface chemical reactions. Finally, the effect of FSDE on the PhC optical properties is assessed by measuring the quality factor of one-dimensional Fabry-Perot PhC cavities. The measured quality factors show a clear trend with the etch depth: the cavity Q increases as the etch depth increases.
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| 2. |
- Berrier, Audrey, et al.
(författare)
-
Feature size effects in chemically assisted ion beam etching of InP-based photonic crystals - art. no. 632707
- 2006
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Ingår i: Nanoengineering: Fabrication, Properties, Optics, and Devices III. - BELLINGHAM, WA : SPIE-INT SOC OPTICAL ENGINEERING. - 0819464066 ; , s. 32707-32707
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Konferensbidrag (refereegranskat)abstract
- This work addresses feature size effects (the lag-effect and roughness development) in chemically assisted ion beam etching (CAIBE) etching of InP-based photonic crystals. Photonic crystal fields with varying hole size and periods were etched with different etching times. The slope of the etch depth versus diameter curves (lag-curves) reveals a hole size dependence, with a critical aspect ratio higher than 25. A model for the etch rate specific to Ar/Cl-2 CAIBE is proposed. We calculate the etch rate using a physico-chemical model which takes in to account the effect of Ar-ion sputtering and surface chemical reactions. In addition, it combines the aspect ratio dependence of the gas conductance of the etched holes. The origin and evolution of the bottom roughness of the etched holes is examined. The impact of the feature size dependence of the etching on the photonic crystal optical properties is then assessed by measuring the quality-factor of one-dimensional Fabry-Perot cavities using the Internal Light Source method, and discussed in terms of hole shape and depth. A systematic trend between the determined quality factor (Q) and the lag-effect is evidenced: Q decreases from about 250 to 60 when the hole depth drops from 5 mu m to 2 mu m.
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| 3. |
- Berrier, Audrey, et al.
(författare)
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Impact of feature-size dependent etching on the optical properties of photonic crystal devices
- 2008
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 103:9, s. 096106-1-096106-3
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Tidskriftsartikel (refereegranskat)abstract
- Feature size dependence in Ar/Cl-2 chemically assisted ion beam etching of InP-based photonic crystals (PhCs) and its influence on the optical properties of PhC devices operating in the band gap are investigated. The analysis of the measured quality factors, the determined mirror reflectivities, and losses of one-dimensional Fabry-Perot cavities clearly demonstrates the importance of feature-size dependent etching. The optical properties show a dramatic improvement up to a hole depth of about 3.5 mu m that is primarily due to a significant reduction in extrinsic losses. However, beyond this hole depth, the improvement is at a lower rate, which suggests that extrinsic losses, although present, are not dominant.
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| 4. |
- El-Kallassi, P., et al.
(författare)
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Optical and local tuning of planar photonic crystals infiltrated with organic molecules
- 2007
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Ingår i: Conference on Lasers and Electro-Optics, 2007, CLEO 2007. - 9781557528346 ; , s. 1375-1376
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Konferensbidrag (refereegranskat)abstract
- We report on the optical tuning of InP-based planar photonic crystals (PhCs) infiltrated with a photoresponsive liquid crystal system. Preliminary results on the local tuning of PhC devices are also presented.
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| 5. |
- El-Kallassi, P., et al.
(författare)
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Optical and local tuning of planar photonic crystals infiltrated with organic molecules
- 2007
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Ingår i: Lasers and Electro-Optics, 2007 European Conference on and the International Quantum Electronics Conference. - 1424409306 - 9781424409303 ; , s. 4387041-
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Konferensbidrag (refereegranskat)abstract
- We report on the optical tuning of InP-based planar photonic crystals infiltrated with a photoresponsive liquid crystal system. Preliminary results on the local tuning of infiltrated structures are also presented.
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| 6. |
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| 7. |
- Martz, J., et al.
(författare)
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Liquid crystal infiltration of InP-based planar photonic crystals
- 2006
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 99:10
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Tidskriftsartikel (refereegranskat)abstract
- A procedure for the infiltration of planar photonic crystals (PhCs) with liquid crystals (LCs) is presented. InP-based PhCs are infiltrated with the nematic LC-K15 in a specially designed high-vacuum chamber. The infiltration technique is validated and systematically characterized by measuring the transmission through the infiltrated PhCs at different temperatures and for different polarizations. The reproducibility and reliability of our procedure are demonstrated and a high filling efficiency is obtained.
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| 8. |
- Martz, J., et al.
(författare)
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Tuning the optical properties of planar photonic crystals by liquid crystal infiltration
- 2005
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Ingår i: Proc SPIE Int Soc Opt Eng. - : SPIE. ; , s. 1-14
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Konferensbidrag (refereegranskat)abstract
- Recently there has been a growing amount of attention devoted to tuneable photonic crystals (PhCs) where the optical response of PhC structures can be dynamically modified. We will show how infiltrating planar PhCs with a synthetic organic material allows the trimming and tuning of their optical properties. The potential of PhC infiltration will be demonstrated for InP-based planar PhCs consisting of a hexagonal array of air holes (hole diameter = 200 - 400 nm; air filling factor = 0.40-0.50) etched through a planar waveguide in which light emitters (i.e. quantum wells) were embedded to enable optical measurements. The PhC pores were infiltrated with LC-K15 (5CB) nematic liquid crystals (LCs) in a specifically designed vacuum chamber, thereby changing the refractive index contrast between the holes and the semiconductor (trimming). Moreover, the possibility of tuning the optical response of PhCs by an external perturbation (i.e. temperature) was demonstrated. The change of the PhC optical properties due to infiltration and temperature tuning was studied both experimentally and theoretically. Experimental measurements were compared to theoretical calculations in order to obtain information on the in-filling efficiency, the LC refractive index, and the molecule orientation inside the holes. In the first case, optical measurements were performed as a function of temperature, whilst the average LC director configuration was determined by comparing transmission spectra in the transverse electric and magnetic polarization directions.
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