Lee Michael W, Grillet Christian, Monat Christelle, Mägi Eric, Tomljenovic-Hanic Snjezana, Gai Xin, Madden Steve, Choi Duk-Yong, Bulla Douglas, Luther-Davies Barry, Eggleton Benjamin J
Centre for Ultrahigh-Bandwidth Devices for Optical Systems, Institute for Photonics and Optical Science, School of Physics, University of Sydney, Sydney, NSW 2006, Australia.
Opt Express. 2010 Dec 6;18(25):26695-703. doi: 10.1364/OE.18.026695.
We investigate the photosensitive and thermo-optic nonlinear properties of chalcogenide glass photonic crystal (PhC) cavities at telecommunications wavelengths. We observe a photosensitive refractive index change in AMTIR-1 (Ge(33)As(12)Se(55)) material in the near-infrared, which is enhanced by light localization in the PhC cavity and manifests in a permanent blue-shift of the nanocavity resonance. Thermo-optic non-linear properties are thoroughly investigated by i) carrying out thermal bistable switching experiments, from which we determined thermal switching times of 63 μs and 93 μs for switch on and switch off respectively and ii) by studying heating of the cavity with a high peak power pulsed laser input, which shows that two-photon absorption is the dominant heating mechanism. Our measurements and analysis highlight the detrimental impact of near-infrared photosensitivity and two-photon absorption on cavity based nonlinear optical switching schemes. We conclude that glass compositions with lower two-photon absorption and more stable properties (reduced photosensitivity) are therefore required for nonlinear applications in chalcogenide photonic crystal cavities.
我们研究了硫系玻璃光子晶体（PhC）腔在电信波长下的光敏和热光非线性特性。我们在近红外波段观察到AMTIR-1（Ge(33)As(12)Se(55)）材料中的光敏折射率变化，这种变化因PhC腔中的光局域化而增强，并表现为纳米腔共振的永久性蓝移。通过以下方式对热光非线性特性进行了深入研究：i）进行热双稳开关实验，从中我们分别确定了开启和关闭时的热开关时间为63 μs和93 μs；ii）通过研究高峰值功率脉冲激光输入时腔的加热情况，结果表明双光子吸收是主要的加热机制。我们的测量和分析突出了近红外光敏性和双光子吸收对基于腔的非线性光学开关方案的不利影响。我们得出结论，因此硫系光子晶体腔中的非线性应用需要具有较低双光子吸收和更稳定特性（降低的光敏性）的玻璃成分。
