Dynamical dispersion engineering in coupled vertical cavities employing a high-contrast grating.

Photon's effective mass is an important parameter of an optical cavity mode, which determines the strength of light-matter interaction. Here, we propose a novel method for controlling the photon's effective mass by using coupled photonic cavities and designing the angular dependence of the coupling strength. This can be implemented by employing a high-contrast grating (HCG) as the coupling reflector in a system of two coupled vertical cavities, and engineering both the HCG reflection phase and amplitude response.

Ultrahigh-speed Si-integrated on-chip laser with tailored dynamic characteristics.

For on-chip interconnects, an ideal light source should have an ultralow energy consumption per bandwidth (operating en-ergy) as well as sufficient output power for error-free detection. Nanocavity lasers have been considered the most ideal for smaller operating energy. However, they have a challenge in obtaining a sufficient output power.

Hybrid III-V/SOI resonant cavity enhanced photodetector.

A hybrid III-V/SOI resonant-cavity-enhanced photodetector (RCE-PD) structure comprising a high-contrast grating (HCG) reflector, a hybrid grating (HG) reflector, and an air cavity between them, has been proposed and investigated. In the proposed structure, a light absorbing material is integrated as part of the HG reflector, enabling a very compact vertical cavity. Numerical investigations show that a quantum efficiency close to 100 % and a detection linewidth of about 1 nm can be achieved, which are desirable for wavelength division multiplexing applications.

Study on differences between high contrast grating reflectors for TM and TE polarizations and their impact on VCSEL designs.

A theoretical study of differences in broadband high-index-contrast grating (HCG) reflectors for TM and TE polarizations is presented, covering various grating parameters and properties of HCGs. It is shown that the HCG reflectors for TM polarization (TM HCG reflectors) have much thicker grating thicknesses and smaller grating periods than the TE HCG reflectors. This difference is found to originate from the different boundary conditions met for the electric field of each polarization.

Ultracompact resonator with high quality-factor based on a hybrid grating structure.

We numerically investigate the properties of a hybrid grating structure acting as a resonator with ultrahigh quality factor. This reveals that the physical mechanism responsible for the resonance is quite different from the conventional guided mode resonance (GMR). The hybrid grating consists of a subwavelength grating layer and an un-patterned high-refractive-index cap layer, being surrounded by low index materials.

Hybrid grating reflector with high reflectivity and broad bandwidth.

We suggest a new type of grating reflector denoted hybrid grating (HG) which shows large reflectivity in a broad wavelength range and has a structure suitable for realizing a vertical cavity laser with ultra-small modal volume. The properties of the grating reflector are investigated numerically and explained. The HG consists of an un-patterned III-V layer and a Si grating.

Polarization-independent high-index contrast grating and its fabrication tolerances.

A polarization-independent, high-index contrast grating (HCG) with a single layer of cross stripes allowing simple fabrication is proposed. Since the cross stripes structure can be suspended in air by selectively wet-etching the layer below, all the layers can be grown at once when implemented for vertical-cavity surface-emitting lasers. We optimized the structure to have a broad and high reflectivity band centered at around 1 μm using a finite difference time domain method, and obtained an 80 nm high reflectivity band centered at 0.

High-index-contrast grating reflector with beam steering ability for the transmitted beam.

High-index contrast grating mirrors providing wave front control of the transmitted light as well as high reflectivity over a broad bandwidth are suggested and both numerically and experimentally investigated. General design rules to engineer these structures for different applications are derived. Such grating mirrors would have a significant impact on low cost laser fabrication, since a more efficient integration of optoelectronic modules can be achieved by avoiding expensive external lens systems.

Numerical methods for modeling photonic-crystal VCSELs.

We show comparison of four different numerical methods for simulating Photonic-Crystal (PC) VCSELs. We present the theoretical basis behind each method and analyze the differences by studying a benchmark VCSEL structure, where the PC structure penetrates all VCSEL layers, the entire top-mirror DBR, a fraction of the top-mirror DBR or just the VCSEL cavity. The different models are evaluated by comparing the predicted resonance wavelengths and threshold gains for different hole diameters and pitches of the PC.

Transverse-mode-selectable microlens vertical-cavity surface-emitting laser.

A new vertical-cavity surface-emitting laser structure employing a thin microlens is suggested and numerically investigated. The laser can be made to emit in either a high-power Gaussian-shaped single-fundamental mode or a high-power doughnut-shaped higher-order mode. The physical origin of the mode selection properties of the new structure is rigorously analyzed and compared to other structures reported in the literature.

High-speed (2.5 Gbps) reconfigurable inter-chip optical interconnects using opto-VLSI processors.

Reconfigurablele optical interconnects enable flexible and high-performance communication in multi-chip architectures to be arbitrarily adapted, leading to efficient parallel signal processing. The use of Opto-VLSI processors as beam steerers and multicasters for reconfigurable inter-chip optical interconnection is discussed. We demonstrate, as proof-of-concept, 2.