Hiroshi Aruga

Integrated Spatial Optical System for Compact 28-Gb/s \(\times \) 4-lane Transmitter Optical Subassemblies

A compact 28 Gb/s × 4-lane transmitter optical subassembly is developed for 100Gb/s Ethernet (100 GbE)/OTU4 applications with a hybrid integrated spatial multiplexer optical system. The system simply comprises three bandpass filters and a mirror, despite the narrow guardband specification. Moreover, by an intensively improved precise lens manipulation technique acting in an upward direction in addition to horizontally and downward, high-coupled power into the single-mode output fiber can be achieved, with resolving the previously reported issue that the controllable direction was limited. Finally, we show that eye diagrams with adequate mask margins (≥15%) and high extinction ratio (≥8 dB) are obtained at 28 Gb/s with a low modulating voltage (≤1.6 Vpp).

Four-channel 25Gbps optical receiver for 100Gbps Ethernet with built-in demultiplexer optics

A compact four-channel 25Gbps receiver with built-in demultiplexer realizes high sensitivity less than −12.1dBm and low cross-talk penalty of less than 0.1dB per channel in 12mm × 17mm × 7mm for the next-generation 100Gbps Ethernet applications.

A wavelength monitor using unequally spaced back-emitting light for tunable LD array

A novel wavelength monitor scheme using unequally spaced back-emitting light for a tunable LD array is proposed. The measured variations in the monitor wavelength are less than +0.15 GHz at the ITU-T grids.

Input-Power and Polarization Insensitive All-Optical Wavelength Converter With Monolithically Integrated Monitor PD and Gain-Controlled SOA

This paper presents a polarization-insensitive semiconductor optical amplifier Mach-Zehnder Interferometer (SOA-MZI) wavelength converter with a wide dynamic range. Direct detection of the wavelength-converted output signal power and feedback control of the signal power input to the SOA-MZI are proposed and are confirmed to be able to reduce the variation with input signal power and polarization. The gain-controlled SOA (GC-SOA) and monitor PD used to implement the feedback control are monolithically integrated into the SOA-MZI wavelength converter. A dynamic range of over 8 dB is obtained for TE and TM polarized input signals NRZ modulated at 43 Gb/s under feedback control, 7 dB better than with no feedback.

Super-splits 10G-EPON system: 256 ONU passive splits with 240 ns dual-rate burst-mode 3R synctime and bi-directionally extended 35.9 dB loss budgets

This first super-splits 10G-EPON demonstration achieved the largest loss budget of 35.9 dB and a fast dual-rate synctime of 240 ns supporting 256 ONU splits with 8.0 Gb/s upstream throughput, highlighting novel self-switching AGC based XFP, 82.5 GS/s CDR and ONU SFP+.

Photodiode Packaging Technique Using Ball Lens and Offset Parabolic Mirror

In this paper, we demonstrated the use of a photodiode (PD) packaging technique that employs a catadioptric system. This optical system consisted of two components: a BK7 ball lens with a diameter of 1.5 mm that was soldered with glass on a hermetic cap and a plastic-molded offset parabolic mirror with a radius of 550 mu m and an offset of 550 mu m. The offset parabolic mirror was mounted above a surface-illuminated InGaAs pin PD with a detective area of diameter 20 mum. When an incident pencil of rays were passed through the ball lens and then perpendicularly reflected by the mirror and impinged upon the PD, compact planar assembling became possible for numerous electrical parts on a can-type header for minimizing parasitic impedance due to wire bonds. The optical system provided a high coupling efficiency of 98% between a single-mode fiber and the PD.

Wavelength-tunable dual-output laser module with rear-side wavelength monitor for micro-ITLA

A novel wavelength-tunable dual-output laser module is proposed. The measured output powers are 13.8 dBm and 10.8 dBm with a low power consumption of 3.0 W. We achieved compactness suitable for a micro-ITLA with no additional external optical components.

Wavelength multicasting accompanied with all-optical modulation format conversion from NRZ-OOK to RZ-BPSK using SOA-MZI wavelength converter

We propose a functional wavelength multicasting scheme accompanied with all-optical NRZ-OOK / RZ-BPSK modulation format conversion, using cross-phase modulation in a SOA-MZI. We experimentally demonstrate error free 4-channel multicasting for 10.7 Gbps input.

High-speed modulation lasers for 100 GbE

100 Gbps Ethernet standard promotes high speed modulation lasers of 25 Gbps. Following electro-absorption modulator integrated ones, distributed feedback lasers are satisfying not only Ethernet application but also future ultra high definition video interfaces.

Distributed feedback laser diode with fast wavelength switching and wide tuning range

In wavelength division multiplexing (WDM) networks, tunable lasers are employed as the light sources [1]. For tunable lasers, the requirement for fast wavelength switching is becoming more and more important recently. In the event of an outage in a WDM system, one of the ways for restoration is optical path switching with wavelength conversion, which is in general required to be completed within 100 ms. For fast wavelength switching, a distributed Bragg reflector laser diode (DBR LD) or an external cavity laser diode (ECLD) is often employed [2] [3]. However, these LDs tend to suffer from wavelength jumping due to mode-hopping. A distributed feedback laser diode (DFB LD) has high stability and reliability, and is widely employed as a light source in a WDM system. However, its switching speed is relatively low because of the slow response of a thermoelectric cooler (TEC). In the previous works, we proposed and demonstrated fast wavelength switching technology with a DFB LD [4][5]. In this paper, we propose a tunable light source with a DFB LD that provides a wide tuning range as well as fast wavelength switching.