Abstract: A digital pulse shaping module for controlling a pulsed laser oscillator according to a digital input waveform is provided. The pulse shaping module includes a clock generator generating a plurality of phase-related clock signals and a shape generator which outputs a digital shape signal corresponding to the digital input waveform in Double Data Rate in response to the clock signals. A DAC converts the digital shape into an analog shape signal. The analog shape signal may be used to control the current source of a laser seed source or modulators in the laser oscillator shaping a seed light signal. Optionally, the pulse shaping module may also output a gate control signal having a predetermined timing relationship with respect to the digital shape signal.

Abstract: A laser diode illuminator device and a method for optically conditioning the output beam radiated from such a device, so that highly-demanding illumination application requirements that call for high output powers within a specified field of illumination can be addressed. At the heart of the device is a two-dimensional stack of laser diode bars wherein the linear array of beamlets radiated by each laser diode bar is optically conditioned through its passage in a refractive-type micro-optics device followed by a cylindrical microlens. The micro-optics device performs collimation of the linear array of beamlets along the fast axis of the bars, and it also acts as a beam symmetrization device by interchanging the divergences of the laser beamlets along the fast and slow axes. The cylindrical microlens is for collimation of the beamlets along the slow axis.

Abstract: A laser diode illuminator device and a method for optically conditioning the output beam radiated from such a device, so that highly-demanding illumination application requirements that call for high output powers within a specified field of illumination can be addressed. At the heart of the device is a two-dimensional stack of laser diode bars wherein the linear array of beamlets radiated by each laser diode bar is optically conditioned through its passage in a refractive-type micro-optics device followed by a cylindrical microlens. The micro-optics device performs collimation of the linear array of beamlets along the fast axis of the bars, and it also acts as a beam symmetrization device by interchanging the divergences of the laser beamlets along the fast and slow axes. The cylindrical microlens is for collimation of the beamlets along the slow axis.

Abstract: A digital pulse shaping module for controlling a pulsed laser oscillator according to a digital input waveform is provided. The pulse shaping module includes a clock generator generating a plurality of phase-related clock signals and a shape generator which outputs a digital shape signal corresponding to the digital input waveform in Double Data Rate in response to the clock signals. A DAC converts the digital shape into an analog shape signal. The analog shape signal may be used to control the current source of a laser seed source or modulators in the laser oscillator shaping a seed light signal. Optionally, the pulse shaping module may also output a gate control signal having a predetermined timing relationship with respect to the digital shape signal.

Abstract: An improved laser diode assembly and a method of making such an assembly are provided. The assembly has a substrate wherein channels are formed to receive laser diodes. The channels have an inwardly tapering shape, with a first side wall generally perpendicular to the front surface of the substrate and a second side wall at an angle with the first side wall. A metallic coating is provided over the front surface and the side walls of the channels, with a break at the bottom of the channels. Laser diode bars are mounted along the first side wall of each channel, and a conductive body such as a metallic wire is wedged between the laser diode bar and the opposite tilted side wall. The laser diode bars and wires are held in place by a solder layer. Advantageously, this assembly can be manufactured with less stringent fabrication tolerances than with known laser diode arrays.

Abstract: A method of optical imaging through a scattering medium is provided in which a fit is made to an inhomogeneous diffusion model. The method facilitates good differentiation between scattering and absorption. The variation of the diffusion curve associated with the presence of an inclusion is considered rather than the diffusion curve itself. An empirical model is provided which describes the variation of the diffusion curve. A linear curve fitting process is performed to provide two parameters, one parameter associated with the scattering property of the inclusion and the other parameter associated with the absorption property of the inclusion.

Abstract: The multiple emitters laser diode assembly comprises a laser diode bar for emitting a laser beam. The laser diode bar comprises a plurality of emitters aligned with respect to each other in a same plane of emission. A graded-index elongated fiber microlens is transversely set at a given distance in front of the laser diode bar for controlling the divergence of the beam. The microlens has an axis of symmetry substantially intersecting the optical axis of each emitter. A mount is provided for positioning the microlens with respect to the laser diode bar. Alternatively, the assembly may comprise a laser diode array for emitting the beam. The laser diode array comprises a plurality of substantially parallel rows of emitters with a substantially regular period between them. An array of graded-index elongated fiber microlenses is positioned substantially parallel to the rows. Each microlens corresponds to one of the rows for collimating the beam generated thereby.

Abstract: The most common method of determining whether a breast contains cancerous tissue utilizes ionizing radiation, i.e. x-rays, which possible have tissue damaging properties. It has been found that lasers can be used as a light source in a breast tissue transillumination process. However, due to the high scattering coefficient (or diffusing properties) of breast tissue, it is not possible to obtain images having good resolution using classical transillumination techniques, even when a laser is used as the light source. When passing through a diffusing medium, a laser pulse decomposes into three classes of photons, namely ballistic, snake-like and diffuse photons. In most practical situations, the ballistic photon portion of a laser pulse, which travels in a straight line, does not pass through the tissue, i.e. only snake-like and diffuse photons pass through the tissue.