Keita Mochizuki

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.

Fast wavelength switching with DFB lasers utilizing thermal compensation

A fast wavelength switching method for ordinary distributed feedback (DFB) lasers utilizing a thermal compensation region outside the laser is proposed. A switching time of 88 ms is obtained. We also demonstrate successive multi-wavelength switching.

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.

Precise lens-assembly techniques based on adhesive bonding and hammering for compact 100GbE TOSA

Two precise lens-assembly techniques based on the adhesive bonding and hammering are proposed. These techniques allow us to realize a compact 100GbE TOSA 15.1 × 6.5 × 5.6 mm which is suitable for the QSFP28 form factor. The measured DC output powers are more than +4.0 dBm which fully achieve the target value of+1.0 dBm with the large margin.

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.

A highly stable multi-beam wavelength monitor for wavelength-stable tunable lasers

A highly stable multi-beam wavelength monitor is proposed. The measured variation in the monitored wavelength with an etalon angular shift of 0.18° is 1.34 GHz, whereas that for a conventional wavelength monitor is 6.54 GHz.