K. Dreyer

Acceleration of gain recovery in semiconductor optical amplifiers by optical injection near transparency wavelength

By using optical injection near the transparency wavelength of semiconductor optical amplifiers, we show experimentally that both the saturation output power and the gain recovery can be greatly improved. By injecting 80 mW of pump power, we observe a 3-dB increase in saturation output power. For 73 mW of pump power, we find a reduction in gain recovery time from over 200 ps down to below 40 ps, while maintaining 14 dB of fiber-to-fiber gain at 1555-nm wavelength.

Tunable dispersion compensation in a 160-Gb/s TDM system by a voltage controlled chirped fiber Bragg grating

We demonstrate for the first time a device that enables practical dispersion management of a 160-Gb/s time-division multiplexer system (return-to-zero duty cycle: 30%). The dynamic dispersion is provided by an integrated chirp-tunable Bragg grating which is capable of recovering 2-ps pulses over a tuning range of 50 ps/nm with system power penalty less than 1.3 dB.

320-Gb/s single-channel pseudolinear transmission over 200 km of nonzero-dispersion fiber

Single-channel transmission at 320 Gb/s is demonstrated over record length of 200 km of nonzero-dispersion fiber. Typical terrestrial amplifier spacing of 100 km is achieved by using pseudolinear transmission and distributed Raman amplification. Stable semiconductor electroabsorption modulators are used in the transmitter, demultiplexer, and clock recovery, and uncorrelated multiplexing is employed in the OTDM transmitter.

All-optical wavelength conversion between 10 and 100 Gb/s with SOA delayed-interference configuration

All-optical wavelength conversion at bit rates from 10 up to 100 Gb/s is experimentally and theoretically investigated employing a fully-integrated semiconductor optical amplifier (SOA) delayed-interference (DI) configuration.

Optoelectronic phase-locked loop with balanced photodetection for clock recovery in high-speed optical time-division-multiplexed systems

An optoelectronic phase-locked loop (PLL) for clock recovery in high-speed optical time-division-multiplexed (OTDM) systems is proposed and experimentally demonstrated. The proposed scheme incorporates a pair of balanced photodetector through which the polarity ambiguity in error signal is resolved, and the cancellation of laser noise enables clock recovery with low timing jitter. Using an electroabsorption modulator as a phase detector, a 10-GHz clock signal with root-mean-square (rms) timing jitter of 300 fs is successfully extracted from 40 and 80 Gb/s return-to-zero (RZ) data stream. A 40- to 10-Gb/s demultiplexing is performed by using the recovered clock signal with no penalty introduced in the bit error rate performance.

Reconfigurable optoelectronic wavelength translation based on an integrated electroabsorption modulated laser array

Reconfigurable optoelectronic wavelength conversion to 11 100-GHz spaced wavelengths is achieved using a wavelength selectable laser array with an integrated electroabsorption (EA) modulator at a bit rate of 2.5 Gb/s. Wide dynamic range at the input from -24.2 to -6.5 dBm is achieved and uniform back-to-back transmission performance is measured for all wavelengths.

320 Gbit/s single-channel pseudo-linear transmission over 200 km of nonzero-dispersion fiber

Single-channel transmission at 320 Gbit/s is demonstrated over record length of 200 km (2/spl times/100 km) of nonzero-dispersion fiber. Semiconductor based transmitter, demultiplexer and clock recovery is employed as well as uncorrelated multiplexing in the transmitter.

A wavelength-tunable semiconductor amplifier/filter for add/drop multiplexing in WDM networks

Reconfigurable channel drop in a wavelength-division multiplexed system is demonstrated using a packaged semiconductor amplifier/filter. The filter is electrically tunable over 9.0 nm with a 0.9-nm width and is used with an optical circulator to demultiplex three 5.0-Gb/s WDM channels spaced by 2.25 nm. A receiver sensitivity improvement and low optical crosstalk is observed over a dynamic range of nearly 10 dB.

A WDM access system architecture based on spectral slicing of an amplified LED and delay-line multiplexing and encoding of eight wavelength channels for 64 subscribers

We propose and demonstrate a novel spectrum-sliced and delay-line multiplexed multiple-wavelength source and its use in a WDM access system. In the proposed system, the pulsed output from an amplified LED is spectrally sliced by a WDM router and multiplexed with short fiber delay lines into individually addressable wavelength channels that can be modulated with an external modulator. By using an Er-fiber amplified 1.55-/spl mu/m LED as the source, eight-channel WDM routers, an 8/spl times/8 star coupler, and monolithically integrated amplifier-modulator chips for data encoding, our experiment demonstrated that a single LED can provide down-stream WDM links to 64 subscribers each at 50 Mb/s.

Monolithically integrated semiconductor LED-amplifier for applications as transceivers in fiber access systems

We have fabricated a monolithically integrated LED-amplifier chip for application as a high-power broad-band transmitter. Amplified LED output of 10 mW and fiber-coupled power of 4 mW was demonstrated. The device can be used as a spectrally-sliced transmitter for wavelength-division-multiplexed networks or as a broad-band transmitter in subcarrier multiple-access systems to eliminate optical beat interference. The amplifier section in the integrated device can also be used as a photodetector. The performance of the device as a transceiver in a WDM multiple-access system operating at a typically proposed local-access data rate of 10 Mb/s was successfully demonstrated.