InGaAsP diode laser

Details of the laser system and the operating conditions employed to control the lasers have been described previously [6]. The system includes two independently operated distributed feedback (DFB) InGaAsP diode lasers tuned over the desired transitions near 1.34 p,m and 1.39 p,m i/ + I s bands)... 

However, a major part of this power improvement was also due to massive gains in diode laser efficiency. Diverse commercial lasers, based upon single crystals, are typically no more than 10% to 20% in efiiciency, but usualty much less. It is typical for a crystal laser to have a "slope" efficiency of 2-5% with outputs less than 10 milliwatts. InGaAsP diode lasers are efficient by these standards with efficiencies greater than 20%. Strained layer quantum-weU structures have been measured with efficiencies in excess of 85% at 1500 nm. wavelength. Typical threshold currents for... 

Currently there are GaAlAs lasers operating in the wavelength region from 790 to 920 nm, and InGaASP lasers in the 1.1-1.6-jLtm region. While diode lasers have some drawbacks as spectral sources, their simplicity and low cost make them quite useful. Much work has been done also in putting these lasers in external cavities to decrease their linewidth and eliminate all extraneous mode structures. 

A review of InGaAsP laser diodes, suitable for operation over the range l.O— 1.7 pm, has been published. 9mW of laser output were obtained from a CdS... 

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