Mads L. Nielsen

Transmission Over 360 km Using a 2.5-Gb/s SOA-Modulator Integrated Full

We present an external-cavity wavelength-tunable laser with a semiconductor optical amplifier-modulator monolithically integrated on the gain chip. The modulator chirp is analyzed, and it is explained how the chirp can be partially cancelled by self-phase modulation in the transmission fiber. Full C-band transmission of 2.5-Gb/s data over 360 km is demonstrated with small power penalty

C

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.

-Band Wavelength-Tunable Transmitter

A gap-mirror technology for integrating a functional section onto a laser gain chip is presented. A semiconductor optical amplifier, implementing several functions, is integrated on the gain chip used in an external cavity laser, and demonstrated as a high-performance variable attenuator and data modulator at 2.5 Gb/s. Control of the mirror properties through the gap geometry is demonstrated, and further optimization is realized by a gap-filling technique, which increases the output power to above 100 mW across the C -band.

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

We propose a widely tunable and low insertion loss loop filter incorporating two ring resonators and an asymmetric Mach-Zehnder interferometer. A semiconductor optical amplifier, phase control section, and loop filter are monolithically integrated on one chip in the InP-InGaAsP material system. The tuning range of 39 nm with side-mode suppression ratio of over 30 dB was demonstrated. The maximum of the total heater power over the tuning range was 84 mW.

Integration of Functional SOA on the Gain Chip of an External Cavity Wavelength Tunable Laser Using Etched Mirror Technology

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.

A Monolithic Wideband Wavelength-Tunable Laser Diode Integrated With a Ring/MZI Loop Filter

We have developed an ECTL based on a gain chip with monolithically integrated VOA and gap mirror. Low power consumption and high output power are demonstrated by optimizing VOA and using gap-filling technique

Demonstration of 10-Gb/s

We present a gap mirror based monolithic integration technology of functional sections on a gain chip for an external cavity wavelength tunable laser (ECTL). The effective reflectivity and coupling coefficient of the gap mirror can be controlled by changing gap length and gap angle. Utilizing this technique, we experimentally demonstrated full C-band ECTL with integrated variable optical attenuator (VOA). Output power of more than 50 mW with VOA operation, SMSR of more than 50 dB were obtained over the entire C-band

C+L

We present an external cavity wavelength tunable laser with an SOA-modulator monolithically integrated on the gain chip. Full C-band transmission of 2.5 Gb/s data over 360 km is demonstrated with small power penalty.

-Band InP-Based Mach–Zehnder Modulator

A monolithically integrated wavelength-tunable laser diode based on a novel loop-filter that consists of two ring resonators and an asymmetric Mach-Zehnder Interferometer (AMZI) is demonstrated with 39-nm tuning range over 30-dB SMSR.