We present theoretical and experimental results of a polarization splitter device that consists of a photonic crystal (PhC) slab, which exhibits a large reflection coefficient for TE and a high transmission coefficient for TM polarization. The slab is embedded in a PhC tile operating in the self-collimation mode. Embedding the polarization-discriminating slab in a PhC with identical lattice symmetry suppresses the in-plane diffraction losses at the PhC-non-PhC interface. The optimization of the PhC-non-PhC interface is thereby decoupled from the optimization of the polarizing function. Transmissions as high as 35% for TM- and 30% for TE-polarized light are reported.
Abstract:We combine photonic crystal and quantum cascade band engineering to create an in-plane laser at terahertz frequency. We demonstrate that such photonic crystal lasers strongly improve the performances of terahertz quantum cascade material in terms of threshold current, waveguide losses, emission mode selection, tunability and maximum operation temperature. The laser operates in a slow-light regime between the M saddle point and K band-edge in reciprocal lattice. Coarse frequency control of half of a terahertz is achieved by lithographically tuning the photonic crystal period. Thanks to field assisted gain shift and cavity pulling, the single mode emission is continuously tuned over 30 GHz.
Nematic liquid crystals are infiltrated into InP-based planar photonic crystals. Optical measurements as a function of temperature and polarization are used to study the average director field configuration in the nanometer-size holes: a planar equilibrium state is found.
A procedure for the infiltration of planar photonic crystals ͑PhCs͒ with liquid crystals ͑LCs͒ 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.
Abstract:We provide a detailed theoretical investigation of two-photon absorption photoconductivity in semiconductor microcavities. We show that a high enhancement of the non-linear response (>10000) can be obtained due to the microcavity effect. We discuss in detail the design and performance (dynamic range, speed) of such a device with the help of an example of a AlGaAs/GaAs microcavity operating at 900nm. This device is promising for low intensity fast autocorrelation and demultiplexing applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.