Nobuo Ohata

Symmetric 10G-EPON ONU transceiver integrated with newly-developed burst-mode pre-bias timing control IC

We developed symmetric 10G-EPON ONU transceiver fully compliant with IEEE802.3av PR30. Output power of +5 dBm, sensitivity of -32.4 dBm, and fast LD turn-on/off time of 10 ns/7 ns were successfully achieved by newly-developed burst-mode pre-bias timing control IC.

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.

43Gbps wavelength converter with wide dynamic range of 14 dB

We demonstrated experimentally a wavelength converter with a wide input power dynamic range of 14 dB for the nonreturn to zero format at 43 Gbps with an extinction ratio exceeding 12 dB.

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.

Wide wavelength bandwidth integrated ROSA using high responsivity resonant cavity 25 Gbps avalanche photodiode

High responsivity resonant cavity APDs were successfully applied to integrated ROSA using wavelength dependence compensation technique. Variation of ROSA responsively in LAN-WDM grid was reduced from 0.23 A/W to 0.05 A/W.

Extended-Temperature Operation (−40 °C to +95 °C) of an EML TOSA Employing an Athermal Optical System

An electroabsorption-modulated laser (EML) transmitter optical sub-assembly (TOSA) employing an athermal optical system has been demonstrated for extended-temperature operation from -40 °C to 95 °C. The output power variation of the TOSA was held to <;0.3 dB over this wide temperature range because of optical compensation using the thermo-optical properties of the plastic lens. A 0.8-dB improvement over the variation without this compensation was confirmed. Since the TOSA has sufficient electrical bandwidth for 20-Gb/s operation, clear eye openings with an extinction ratio of over 9.7 dB were obtained over the wide temperature range. The heat sink, the size of which was optimized for operation of the EML at 55 °C, enabled the TOSA to operate over the wide temperature range without thermal runaway. As a result, power consumption of <;0.42 W was achieved over the temperature range.