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A widely tunable wavelength converter utilizing a separate absorption and modulation configuration and only dc bias connections is demonstrated. The device integrates an SG-DBR laser with a traveling-wave electroabsorption modulator and an optically pre-amplified receiver and introduces a simplified bias scheme by the inclusion of passive resistor and capacitor circuit elements. We discuss a the design of these passive elements and their compatibility with fabrication of photonic integrated circuits. The device demonstrates over 12 GHz optical bandwidth and error free 10 Gb/s wavelength conversion is achieved with less than 2.5 dB power penalty over 25 nm of output tuning. [ABSTRACT FROM PUBLISHER]

In this paper, we present a coherent receiver based on an optical phase-locked loop (PLL) for linear phase demodulation. The receiver concept is demonstrated at low frequency. For high-frequency operation, monolithic and hybrid integrated versions of the receiver have been developed and experimentally verified in an analog link. The receiver has a bandwidth of 1.45 GHz. At 300 MHz, a spurious free dynamic range (SFDR) of 125 dB ldr Hz2/3 is measured. [ABSTRACT FROM PUBLISHER]

We report on two novel approaches to improve the differential quantum efficiency (DQE) of widely tunable 1.55-μm lasers: the bipolar cascade sampled grating distributed Bragg reflector (BC-SGDBR) laser and the gain-levered SGDBR (GL-SGDBR) laser. Each is fabricated on a robust InGaAsP/InP photonic integrated circuit platform. The lasers demonstrate improved direct modulation performance over conventional SGDBR lasers. The BC-SGDBR laser was also monolithically integrated with a semiconductor optical amplifier and photodetector receiver in order to perform wavelength conversion. Error free wavelength conversion at 2.5 Gb/s and improvements in conversion efficiency are demonstrated. [ABSTRACT FROM PUBLISHER]

An experimental analysis of the electrical properties of traveling-wave electroabsorption modulators with undercut waveguides is presented. Modulators of varying ridge widths and amounts of undercut are fabricated and tested to compare characteristic impedance, effective index, microwave loss, and optical bandwidth. We demonstrate effective velocity matching and >40-GHz 3-dB bandwidth for a 400-mum-long device. [ABSTRACT FROM PUBLISHER]

A novel two-tone measurement technique for characterizing distortion in optical phase modulators is proposed and demonstrated. The technique is used to characterize an InGaAsP-InP modulator in a monolithically integrated receiver. Results for forward and reverse bias conditions in the modulator show a phase IP3 of 7.2pi and 0.97pi rad, respectively [ABSTRACT FROM PUBLISHER]

Waveguide uni-traveling-carrier photodiodes (UTC-PDs) have been fabricated and tested. Output saturation currents greater than 40 mA at 1 GHz are demonstrated for a 10 mumtimes150mum photodiode (PD). The third-order intermodulation distortion is also measured and exhibits a third-order output intercept point of 43 dBm at 20 mA and 34 dBm at 40 mA for this same PD. UTC-PDs with geometries of 5 mumtimes100 mum and 10 mumtimes100 mum are also compared and it is shown that a wider waveguide PD has improved saturation characteristics due to the lower optical power density which reduces the saturation at the front end of the device [ABSTRACT FROM PUBLISHER]