Yasumasa Suzaki

Hybrid integration of spot-size converted laser diode on planar lightwave circuit platform by passive alignment technique

An index alignment technique was developed for a planar lightwave circuit platform. The technique was successfully applied to the hybrid integration of a spot-size converted laser diode on the platform. The fabricated modules exhibited an average coupling loss of 4.2 dB and a maximum optical output power of 10 mW at an injection current of 70 mA.

A torus datacenter network based on OPS/OCS/VOCS enabled by smart flow management

We present an energy-efficient, low-latency, torus-topology intra-data center network with the deployment of 100-Gb/s hybrid optoelectronic routers, where OPS, OCS and virtual OCS are all supported on a single hardware platform enabled by smart flow management.

Enhancement of electric field-induced refractive-index variation in a (GaInAsP)(InAs)/InP asymmetric multiple-quantum-film (MQF) structure

The authors report the field-induced refractive-index variation in (GaInAsP)/InP asymmetric quantum-film structures. An enhancement of an electric field-induced refractive-index variation due to the quantum confined Stark effect was theoretically found in the GaInAsP-InAs/InP asymmetric quantum-film structure, especially in a low electric-field regime. Almost two times higher sensitivity was experimentally confirmed in a 40-period GaInAsP (8 nm)-InAs (0.3-0.6 nm)/InP (8 nm) asymmetric multiple quantum-film (MQF) structure in comparison with a symmetric one without an InAs layer at an applied electric field less than 6 V/ mu m.<<ETX>>

High-gain array of semiconductor optical amplifier integrated with bent spot-size converter (BEND SS-SOA)

We propose a high-gain semiconductor optical amplifier with an integrated bent spot-size converter (BEND SS-SOA). A straight active waveguide enables us to use a pn-buried heterostructure (pn-BH) with a high current-blocking effect and uniform characteristics. We can optimize a bent spot-size converter waveguide to provide low optical feedback from the facets and high-coupling efficiency to a flat-end optical fiber with low radiation loss due to the bend. The devices we fabricated achieve a high fiber-to-fiber gain of 18 dB with a coupling efficiency of -3.5 dB, and we have demonstrated a four-channel array with uniform characteristics.

Demonstration of packet-by-packet wavelength conversion from FP-LD light to ITU-T grid wavelengths

We demonstrated packet-by-packet wavelength conversion from Fabry-Perot laser diode (FP-LD) light to four ITU-T grid wavelengths. To achieve this we used a cross-phase modulation (XPM) wavelength converter and an arrayed-waveguide grating (AWG) router. Good feasibility was obtained at 2.5-Gb/s modulation. Selective wavelength conversion as described here is indispensable for the all-optical networks of future, in which optical signal sources without wavelength control will be used at user-end terminals.

High-coupling efficiency of a 1.3-/spl mu/m spot-size converter integrated laser diode with pn-buried heterostructure for high-temperature operation

We propose a novel design concept for low-loss coupling with high laser performance in a spot-size converter integrated laser diode (SS-LD) with a pn-buried heterostructure (pn-BH) and demonstrate both the good coupling efficiency and high laser performance. We clarify that a high position and a high doping concentration of an n-InP current blocking layer in the pn-BH are favorable for high-coupling efficiency with a single-mode fiber by a two-dimensional (2-D) finite-element method-based calculation. By using the proposed concept, low-loss coupling of 1.6 dB with a low threshold current of 5.5 mA at room temperature and 19.6 mA even at 85/spl deg/C was achieved experimentally.

Temperature- and polarization-insensitive responsivity of a 1.3-/spl mu/m optical transceiver diode with an integrated spot-size converter

We have demonstrated an optical transceiver diode integrated with a spot-size converter. We clarify that the design of a detection layer is essential for the temperature- and polarization-insensitive characteristics of the responsivity. Because the detection layer was introduced, 0.65 dB of responsivity deviation was obtained in the wide temperature range of -10/spl deg/C-85/spl deg/C with a high laser performance. A spot-size converter enables the coupling loss to be 1.8 dB for a flat-end optical fiber. The frequency response was also obtained up to 1 GHz in both laser and detector modes.

100-Gb/s Optical Packet Switching Technologies for Data Center Networks

The hybrid optoelectronic router (HOPR) can efficiently allow the realizing of a highly-scalable and energy-efficient DC network. We present the recent developments on the 100-Gb/s underlying technologies that enable HOPR’s necessary functions.

Integrable ultralow-power nanophotonic devices on InP photonic crystals

Photonic crystal nanocavities are expected to greatly reduce the size and energy consumption of various optical devices. We have demonstrated this feature in all-optical switches and random access memories for on-chip nanophotonic integration.

Semiconductor-based advanced integrated devices for WDM networks

Semiconductor monolithic integration is a key technology for realizing various functional WDM devices. In this paper, our monolithically integrated devices, which are the WDM channel selector and the WDM modulator, are reviewed.