J. Singh

Optical switching in the twin-guide Fabry-Perot laser amplifier

A recently developed theory of the twin-guide Fabry-Perot laser amplifier has been extended to include the case of optically induced switching. The effect of feedback from the facets serves to dramatically decrease the optical power required for switching as compared to that for a traveling-wave amplifier, but at the expense of accurate control of input wavelength. Switching is predicted at input powers on the order of microwatts, in good agreement with a first experimental demonstration of the effect. >

A novel twin-ridge-waveguide optical amplifier switch

A novel twin ridge-waveguide optical amplifier switch is reported. The technique of hydrogen passivation of acceptors has been applied to decrease the current spreading in the region between the ridges. The incorporation of a passive waveguide below the active waveguide leads to the result that using 1.53 mu m TE polarized light, through and cross states, each with only 1 dB insertion loss, fiber-to-fiber, can be selected in a device of 360 mu m length by varying the currents to each ridge with a total current of 140 mA. A minimum crosstalk of less than -33 dB was achieved when the cross state was selected. This is the first report of a twin ridge-waveguide amplifier switch with such a low-loss, low-polarization sensitivity, and low crosstalk.<<ETX>>

An optical tap based on the twin waveguide laser-amplifier with asymmetric flared output waveguides

An optical tap based on the twin waveguide laser-amplifier with asymmetric flared output waveguides is presented. The new optical tap exhibits gain, allows the tap channel gain to be electrically controlled over a dynamic range of 30 dB, without greatly affecting the through channel gain and is optically broadband. The general features of the optical tap can be understood from coupled mode theory.<<ETX>>

Reactive ion etching of zinc doped InP using methane and hydrogen: Assessment of the degree and extent of changes in surface carrier concentration

Reactive ion etching of zinc‐doped InP has been assessed in terms of the degree and extent of the passivation (reduction in carrier concentration). It is found that passivation of acceptors depends on the rf power as well as etching times used. Reduction in carrier concentration as large as three orders of magnitude can be achieved by the use of powers as low as 0.5 W/cm2 for 10 min. The effect of this passivation on the characteristics of semiconductor lasers is reported.