L. C. Chiu

On the linewidth enhancement factor α in semiconductor injection lasers

A simple model for the linewidth enhancement factor α and its frequency dependence in semiconductor lasers is presented. Calculations based on this model are in reasonable agreement with experimental results.

A new infrared detector using electron emission from multiple quantum wells

A new type of infrared photodetector using free electron absorption in a heavily doped GaAs/GaAlAs quantum well structure has been demonstrated. Preliminary results indicate a strong response in the near infrared with a responsivity conservatively estimated at 200 A/W. The structure can potentially be tailored during fabrication for use in several infrared bands of interest, including the 3 to 5 micron band and the 8 to 10 micron band.

Application of internal photoemission from quantum-well and heterojunction superlattices to infrared photodetectors

Abstract Calculation has been performed for the free carrier and intervalence band absorption in quantum-well structures. Potential application of the enhanced absorptions to near-infrared photodetectors is discussed.

Auger recombination in quantum-well InGaAsP heterostructure lasers

Interband nonradiative Auger recombination in quantum-well InGaAsP/InP heterostructure lasers has been calculated. It is found that the Auger rate is much reduced in the quasi two-dimensional quantum-well lasers. This suggests that the temperature sensitivity of quantum-well InGaAsP lasers is much less than ordinary structures with much higher values of T 0 at around room temperatures.

Direct measurement of the carrier leakage in an InGaAsP/InP laser

Carrier leakage over the heterobarrier in an InGaAsP/InP laser is measured directly in a laser-bipolar-transistor structure. Experimental results indicate a significant amount of carrier leakage under normal laser operating conditions.

Picosecond Carrier Dynamics and Laser Action in Optically Pumped Buried Heterostructure Lasers

We report the observation of picosecond optical pulses and unusual pulse structures from optically pumped buried heterostructure semiconductor lasers. A model which considers the hot electron and hole energy distributions dynamically accounts well for our experimental findings. The results are relevant to the problem of the limiting response time of semiconductor lasers.

Analysis and performance of a picosecond dye laser amplifier chain

A mathematical analysis is presented for dye laser amplifier chains used to amplify cw mode‐locked dye laser pulses up to the gigawatt regime. The model permits a discussion of the important aspects of the problem such as gain saturation, pulse shaping, and the optimization of pumping efficiencies. Experimentally, an amplifier chain has been demonstrated which is simple in design and operation without sacrificing high performance. A frequency doubled Q‐switched Nd:YAG oscillator alone is used to longitudinally pump three identical Brewster cells with the same flowing dye solution in each. The amplifier boosts the output of a synchronously mode‐locked dye laser to obtain ∼0.5 mJ≲1 psec pulses over a ∼400 A bandwidth. These pulses are suitable for efficient Raman shifting, frequency mixing, and continuum generation to vastly extend the spectral range of the system. Some experimental results are presented to support the mathematical model.

Carrier leakage and temperature dependence of InGaAsP lasers

A direct measurement of electron and hole leakage in InGaAsP/InP lasers has been carried out. The effect of electron leakage on the temperature sensitivity of InGaAsP/InP lasers has been revealed.

Study and application of the mass transport phenomenon in InP

A study of the mass transport phenomenon in InP is presented. Conditions and possible explanation for the transport process are discussed. Characteristics of the mass transported InP homojunctions are described and compared with those in the InP–InGaAsP heterojunctions. Effects of the mass transported junction on laser performance are discussed.

Interband Auger recombination in InGaAsP

The interband Auger recombination lifetimes of two Auger processes have been calculated to correlate measured threshold current densities and carrier lifetimes for InGaAsP and InGaAsSb lasers. Good aggreement with experimental data was obtained for lasers with low nominal threshold current densities. These results demonstrate the importance of Auger recombination in the threshold characteristics of InGaAsP/InP lasers.