The nonlinearity difference in the two passbands of a distributed-feedback semiconductor laser amplifier was studied experimentally. A theoretical explanation was given by using the transmission matrix approach. The difference of nonlinearity in the two passbands was found to be enhanced greatly by the mechanism of asymmetric facet reflection.

By exploiting nonlinear effects in a semiconductor optical amplifier, different functionalities for all-optical digital signal processing are implemented. In particular we demonstrate the logic functions of integrated addition-subtraction and demultiplexing. The all-optical realizations are based on semiconductor optical amplifier (SOA) and Mach–Zehnder interferometer (MZI), which represent one...

The passive sections of a monolithic device must have a wider bandgap than the active regions to reduce losses due to direct interband absorption. Such bandgap engineering is usually realized by complicated regrown butt-joint or selective-area growth techniques. We, however, have developed a simple, flexible and low-cost alternative technique – quantum well intermixing (QWI) – to increase the b...

The field of optical communications is moving toward the realization of photonic networks with wavelength division multiplexing (WDM) utilizing the full bandwidth of optical fibers. Conventionally, an erbium-doped fiber amplifier (EDFA) and a semiconductor optical amplifier (SOA) are used for amplifying an optical signal in optical communications. SOAs can contribute to this and offer the key a...

In this paper 16 channels DWDM system at 10Gbps has been investigated with Semiconductor optical amplifier at 0.8 nm channel spacing and the performance has been calculated on the basis of bit error rate, quality factor and optical output power. It is observed that the signal can be transmitted with acceptable BER and Q-factor using Semiconductor optical amplifier at low signal input power of -...

Chirp-controlled optical modulation is demonstrated using a voltage division scheme applied to a long-section phase modulator to compensate for the positive chirp of an electroabsorption modulator arranged in a tandem configuration. Both modulators are integrated with a semiconductor optical amplifier (SOA) and a sampled-grating distributed Bragg reflector (DBR) laser. The effective chirp facto...

With the advancement of nanoscale semiconductor technology,semiconductor optical amplifiers are used to amplify and process all-optical signals. Inthis paper, with the aim of calculating the gain of quantum dot semiconductor opticalamplifier (QD-SOA), two groups of rate equations and the optical signal propagatingequation are used in the active layer of the device. For t...

Active-mode locking of semiconductor lasers has pro­ duced optical pulses as short as 0.58 ps.! This result was achieved using the positive portion of a 16 GHz sinusoid as an electrical drive signal. For many applications, such as electro-optic sampling, it is more useful to have the mode­ locked optical pulses at a much lower repetition rate. This requires an electrical drive source that produ...

We report on a study of a 698 nm extended cavity semiconductor laser with intracavity narrowband optical feedback from a whispering gallery mode resonator. This laser comprises an ultrahigh-Q (>10(10)) resonator supporting stimulated Rayleigh scattering, a diffraction grating wavelength preselector, and a reflective semiconductor amplifier. Single longitudinal mode lasing is characterized with ...