T. Morimoto

1.55-μm wavelength-selectable microarray DFB-LD's with monolithically integrated MMI combiner, SOA, and EA-modulator

We developed compact (1.136 mm/sup 2/) eight-channel wavelength-selectable microarray distributed feedback laser diodes (DFB-LDs) with a monolithically integrated 8/spl times/1 multimode-interference (MMI) optical combiner, a semiconductor optical amplifier (SOA), and an electro-absorption (EA) modulator. By using /spl plusmn/10/spl deg/C thermal tuning, an addressable wavelength range of 15.3 nm with uniform device characteristics and 2.5-Gb/s modulation performance were successfully demonstrated.

Wavelength-selectable microarray light sources for S-, C-, and L-band WDM systems

We report on the first demonstrated near-complete coverage of the S-, C-, and L-bands using six different ranges of wavelength-selectable microarray light sources (WSLs) based on a distributed-feedback (DFB) laser diode (LD) array. The six devices were fabricated on only two wafers. Each device has a tuning range of more than 15 nm, a sidemode suppression ratio of over 40 dB, and a fiber-coupled power greater than around 10 mW.

Wavelength-selectable light sources fabricated using advanced microarray-selective epitaxy

An advanced microarray-selective epitaxy with wider open-stripes has been developed for simple fabrication of distributed-feedback laser diode array-based high-power wavelength-selectable light sources. More than 40-mW fiber-coupled power and 50-dB sidemode suppression ratio over 9.2-nm wavelength were achieved.

1.55 /spl mu/m wavelength-selectable microarray DFB-LDs with integrated MMI combiner, SOA, and EA-modulator

We developed compact (1.136 mm/sup 2/) eight-channel wavelength selectable microarray DFB-LDs with monolithically integrated 8/spl times/1 MMI combiner, S0A, and EA-modulator. The wavelength tuning range of 15.3 nm with uniform device characteristics and 2.5 Gbit/s modulation performance were successfully demonstrated.

SOA-Booster Integrated Mach–Zehnder Modulator: Investigation of SOA Position

Integration of a booster semiconductor optical amplifier (SOA) is an efficient way of overcoming losses in InP based Mach-Zehnder modulators. We analyze the impact of locating the SOA before and after the MZM, respectively, in terms of output power and signal integrity at 10 Gb/s, both experimentally and theoretically. For a device with 10 dB MZM loss it is found that, for a fixed power consumption, locating the SOA after the MZM provides 7-9 dB higher output power. This advantage is reduced for lower MZM losses but remains significant. With the SOA after the MZM, the gain is restricted by dynamic saturation effects (waveform distortion), which is not the case if the SOA is at the input of the MZM. The waveform distortion is accompanied by a spectral red-shift, which degrades the transmission performance. Simulations show that for MZM losses below ~4 dB, locating the SOA before the MZM can provide a higher power with no waveform distortion and negative chirp, at the cost of a higher SOA gain. For higher MZM losses it is unfeasible to locate the SOA before the MZM, due to a prohibitively large power consumption.

Multirange wavelength-selectable microarray light sources simultaneously fabricated on a wafer covering the entire C-Band

We developed high-performance distributed feedback array-based wavelength-selectable light sources (WSLs), covering the entire C-band with five simultaneously fabricated devices. We fabricated five different range WSLs on a wafer, each with a unique 8-nm tuning range to cover 40 100-GHz-spaced channels. Uniform characteristics, such as an Ith of 8.3/spl plusmn/1.2 mA, a sidemode suppression ratio of over 45 dB, and a fiber-coupled power greater than 8.5 mW were obtained.

Demonstration of 10-Gb/s

We present a 10-Gb/s InP-based Mach-Zehnder modulator with ruthenium (Ru)-doped buried heterostructure waveguides. C- and L -band operation is demonstrated, including transmission over 100 km of single-mode fiber for 1528-1600 nm.

C+L

In this letter, we have simultaneously fabricated five wavelength-selectable microarray light sources (WSLs), each having a different wavelength range integrated with an electroabsorption (EA) modulator on a single wafer. We also introduced a novel device configuration scheme for wavelength-independent modulation. The five EA-WSLs fully covered the entire C-band and had a low uniform threshold current of 6 /spl plusmn/ 1 mA at 25/spl deg/C. Wavelength-independent extinction characteristics were obtained over a tuning wavelength range of 8 nm, and 2.5-Gb/s transmission over 600 km was successfully achieved.