Abstract: We have developed a high-performance, low-volume, low-weight, and low-power sensor based on a self-sustaining oscillator. The techniques described here may be used for sensing various fields; we demonstrate magnetic sensing. The oscillator is based on a dielectric resonator that contains paramagnetic defects and is connected to a sustaining amplifier in a feedback loop. The resonance frequency of the dielectric resonator shifts in response to changes in the magnetic field, resulting in a shift in the frequency of the self-sustaining oscillator. The value of the magnetic field is thereby encoded in the shift or modulation output of the self-sustaining oscillator. The sensor as demonstrated uses no optics, no input microwaves, and, not including digitization electronics, consumes less than 300 mW of power and exhibits a sensitivity at or below tens of pT/?{square root over (Hz)}. In some implementations, the sensor is less than 1 mL in volume.

Abstract: A fiber laser system includes at least one optical fiber with a core and a cladding and is operative at a first wavelength larger than 2000 nm. The operative first wavelength is preferably chosen to maximize transmission through the atmosphere. At least one optical pumping system includes one or more pumping fiber lasers also doped with thulium for pumping the optical fiber. The pumping system is operative at a second, shorter wavelength close to the first wavelength for low quantum defect pumping. The core of the optical fiber is doped with thulium at a doping concentration greater than one weight % to reduce absorption losses in the core.

Abstract: A surgical technique for removing corneal tissue with scanned infrared radiation is disclosed which utilizes short mid-infrared laser pulses to provide a tissue removal mechanism based on photospallation. Photospallation is a photomechanical ablation mechanism which results from the absorption of incident radiation by the corneal tissue. Since photospallation is a mechanical ablation process, very little heat is generated in the unablated adjacent tissue. The disclosed surgical system includes a scanning beam delivery system which allows uniform irradiation of the treatment region and utilizes low energy outputs to achieve controlled tissue removal. A real-time servo-controlled dynamic eye tracker, based on a multiple-detector arrangement, is also disclosed which senses the motion of the eye and provides signals that are proportional to the errors in the lateral alignment of the eye relative to the axis of the laser beam.

Abstract: A laser parametric generator for surgical applications is disclosed which utilizes short-pulse, mid-infrared radiation. The mid-infrared radiation may be produced by a pump laser source, such as a neodymium-doped laser, which is parametrically downconverted in a suitable nonlinear crystal to the desired mid-infrared range. The short pulses reduce unwanted thermal effects and changes in adjacent tissue to potentially submicron-levels. The parametrically converted radiation source preferably produces pulse durations shorter than 25 ns at or near 3.0 &mgr;m but preferably close to the water absorption maximum associated with the tissue. The down-conversion to the desired mid-infrared wavelength is preferably produced by a nonlinear crystal such as KTP or its isomorphs. In one embodiment, a non-critically phased-matched crystal is utilized to shift the wavelength from a near-infrared laser source emitting at or around 880 to 900 nm to the desired 2.9-3.0 &mgr;m wavelength range.

Abstract: A transversely pumped solid state laser includes: a solid state gain medium having thickness, width and longitudinal dimensions; means for forming a laser cavity with the medium for generating a laser beam along the longitudinal dimension; and a semiconductor laser pump source for directing a collimated pump beam to the medium along the width dimension transversely to the longitudinal dimension constrained toward the center of the medium and having a width which is substantially shorter than the longitudinal dimension of the medium for spacing the edges of the collimated beam away from the longitudinal ends of the medium to reduce thermomechanical distortion of the longitudinal ends of the medium and consequent distortion of the laser beam.

Abstract: A three-color coherent light system includes a laser source for generating a laser beam in the 1000-1100 nm wavelength region; means, responsive to the laser source, for generating the second harmonic of the laser beam; an optical parametric oscillator for providing a signal beam and an idler beam; means for splitting the second harmonic of the laser beam into a first beam for providing a source of coherent green light and a second beam for pumping the optical parametric oscillator to produce the signal and idler beams; means for generating the second harmonic of the signal beam as a source of coherent blue light; and means for generating the second harmonic of the idler beam as a source of coherent red light.