Abstract: A semiconductor laser oscillator structure and method is described having a tapered gain region in one-half of a laser cavity and a confocal oscillator region in another half of the cavity. An aperture is formed between two pairs of cavity spoilers located between the two cavity halves. One pair of spoilers is provided for receiving light which is reflected off of an output facet back into the semiconductor and removing it from the gain region. The other pair of spoilers removes light reflected from a curved mirror surface formed at the end of the other laser cavity half.

Abstract: A dual-chamber pacemaker for confirming pacemaker mediated tachycardia (PMT) after initial detection. The minimum V-V pacing interval is extended to be slightly longer than the interval of the sensed atrial rate. If the A-V Delay intervals in successive cycles remain constant, as opposed to progressively increasing in Wenckebach fashion, then PMT is confirmed.

Abstract: A semiconductor laser gain structure having a tapered gain region comprising cavity spoilers for receiving light which is reflected off of the output facet back into the semiconductor and removing it from the gain region so as to reduce or eliminate self-oscillation. The boundaries of the gain region are also designed to have a very low refractive index gradient so as to minimize reflection of light off of the boundaries back into the gain region. The gain structure may be embodied in a semiconductor laser oscillator or semiconductor laser amplifier depending on whether the input facet is or is not, respectively, anti-reflection coated. The output facet is anti-reflection coated in either embodiment.

Abstract: A semiconductor laser gain structure having a tapered gain region comprising cavity spoilers for receiving light which is reflected off of the output facet back into the semiconductor and removing it from the gain region so as to reduce or eliminate self oscillation. The boundaries of the gain region are also designed to have a very low refractive index gradient so as to minimize reflection of light off of the boundaries back into the gain region. The gain structure may be embodied in a semiconductor laser oscillator or semiconductor laser amplifier depending on whether the input facet is or is not, respectively, anti reflection coated. The output facet is anti-reflection coated in either embodiment.

Abstract: The invention relates to an electrically operated fiber optical switch for circularly polarized light. The switch comprises an input 3-dB fiber optic coupler, a Faraday effect fiber optic phase rotator and an output 3-dB fiber optic coupler, all three providing dual fiber optic paths. The input 3-dB coupler divides the light waves between two oppositely wound optical fibers in the Faraday effect phase rotator. The magnetic fields in the phase rotator are adjusted to produce the desired (e.g. .+-..pi./2 radians) relative phase delays between the divided light waves, the sign of the relative phase being dependent on current direction. When the light waves are recombined in the output 3-dB couplers, cancellation will occur in one or the other output fiber as a function of the direction of the magnetic field. The arrangement provides rapid switch operation by reversing the current direction in a magnetic field producing winding.