Phase sensitive amplification (PSA) is an attractive technology for integrated all-optical signal processing, due to it's potential for noiseless amplification, phase regeneration and generation of squeezed light. In this talk I will review our results on implementing four-wave-mixing based PSA inside integrated photonic devices. In particular I will discuss PSA in chalcogenide ridge waveguides and silicon slow-light photonic crystals. We achieve PSA in both pump- and signal-degenerate schemes with maximum extinction ratios of 11 (silicon) and 18 (chalcogenide) dB. I will further discuss the influence of two-photon absorption and free carrier effects on the performance of silicon-based PSAs.
Semiconductor optical waveguides have been the subject of intense study as both fundamental objects of study, as well as a path to photonic integration. In this talk I will focus on the nonlinear evolution of optical solitons in photonic crystal waveguides made of semiconductor materials. The ability to independently tune the dispersion and the nonlinearity in photonic crystal waveguides enables the examination of completely different nonlinear regimes in the same platform. I will describe experimental efforts utilizing time-resolved measurements to reveal a number of physical phenomena unique to solitons in a free carrier medium. The experiments are supported by analytic and numerical models providing a deeper insight into the physical scaling of these processes.
In recent years integrated waveguide devices have emerged as an attractive platform for scalable quantum tech- nologies. In contrast to earlier free-space investigations, one must consider additional effects induced by the media. In amorphous materials, spontaneous Raman scattered photons act as a noise source. In crystalline materials two-photon absorption (TPA) and free carrier absorption (FCA) are present at large intensities. While initial observations noted TPA affected experiments in integrated semiconductor devices, at present the nuanced roles of these processes in the quantum regime is unclear. Here, using single photons generated via spontaneous four-wave mixing (SFWM) in silicon, we experimentally demonstrate that cross-TPA (XTPA) between a classical pump beam and generated single photons imposes an intrinsic limit on heralded single photon generation, even in the single pair regime. Our newly developed model is in excellent agreement with experimental results.
We compare the energy performance of four-wave mixing in nanowires and slow-light photonic crystals and
outline the regimes where each platform exhibits salient advantages and limitations, including analysis of the
impact of future fabrication improvement. These results suggest a route towards energy efficient silicon integrated
Compactness, massive integration of multiple functions on a single chip and power consumption are crucial for
transmission of large aggregated bit rates at short distance. Efficient implementation of data processing at the
optical level are very attractive. Here we present a technology for implementing ultra-fast switching with recordlow
energy·recovery time product. We developed high-quality photonic crystal micro-resonators based on III-V
semiconductors. The very short carrier lifetime of nano-pattened Gallium Arsenide enabled us to achieve 6 ps
recovery time, thus enabling operations beyond the 100Gb/s rate. For broadband operation, highly nonlinear
waveguides with low insertion loss have been demonstrated.
We present the design and fabrication of an all-optical bistable device in AlGaAs. The material is known to have a nonlinear figure-of-merit that is in larger silicon and thus well suited to nonlinear experiments. We employ theoretical analysis consisting of both analytical models and finite-difference time-domain (FDTD) methods to ensure robust design and to estimate the power threshold of the proposed device. The proposed nanocavity experiment suggests low powers (~102 μW) and ultra fast switching (~ps) on chip limited only by photon lifetime. This is an improvement over silicon based experiments, which have demonstrated ~ 100 nanosecond responses but intrinsically bounded by free-carrier dynamics . In this manuscript, we will elaborate on theoretical and experimental considerations required to implement a low power, ultrafast bistable device that forms a fundamental building block in all-optical logic operations.
Proc. SPIE. 6327, Nanoengineering: Fabrication, Properties, Optics, and Devices III
KEYWORDS: Nanostructures, Finite-difference time-domain method, Switching, Waveguides, Photonic crystals, Near field scanning optical microscopy, Near field, Negative refraction, Near field optics, Photonic nanostructures
Recent important advances in subwavelength nanostructures offer extraordinary control over the properties of
light. We can now manipulate the propagation, storage, and generation of light, as well as practically
prescribe light-matter interaction based on first-principles. Photonic crystals, in particular, offer the unique
ability for arbitrary control of dispersion as well as ultrahigh quality factor (Q) and modal volume (Vm)
nanocavities. In this talk, we will present, to our knowledge, the first near-field experimental observations of
near-infrared subwavelength imaging in negative refraction photonic crystals, as well as discuss our efforts in
enhanced nonlinearities in photonic crystal nanocavities.
Recent important advances in subwavelength nanostructures offer extraordinary control over the properties of light. We can now manipulate the propagation, storage, and generation of light, as well as practically prescribe its matter interaction properties based on first-principles. Photonic crystals, in particular, offer the unique ability to achieve ultrahigh Q/Vm nanocavities, and the arbitrary control of dispersion characteristics to increase photon-matter interaction times. In addition, silicon photonics offer the unique opportunity towards the convergence of electronics and photonics in a monolithic silicon platform for unprecedented information processing capacity. In this talk, we will review critical advances in these arenas, as well as present our developments in fundamental and applied studies of optics in subwavelength nanostructures.