Abstract: In order to maximize the dynamic range and depth of field for a depth camera used in a time of flight system, the light source is modulated at a plurality of different frequencies, a plurality of different peak optical powers, a plurality of integration subperiods, a plurality of lens foci, aperture and zoom settings during each camera frame time. The different sets of settings effectively create subrange volumes of interest within a larger aggregate volume of interest, each having their own frequency, peak optical power, lens aperture, lens zoom and lens focus products consistent with the distance, object reflectivity, object motion, field of view, etc. requirements of various ranging applications.

Abstract: A wavelength selective device including an arrayed waveguide grating is disclosed. The wavelength selective device includes a MEMS mirror, which couples light from an input port to an elongate aperture of an input star coupler or slab of the arrayed waveguide grating. A controller tilts the MEMS mirror in response to a sensed temperature change of the arrayed waveguide grating, thereby lessening a sensitivity of the arrayed waveguide grating to the temperature change. The MEMS mirror can also be tilted to shift wavelengths of the wavelength channels of the arrayed waveguide grating by pre-defined amounts upon receiving a corresponding remote command.

Abstract: An optical fiber breakage point may be located by coupling to the optical fiber an out-of-band optical test signal modulated at a periodic modulation pattern. A distance to the breakage point may be determined from a difference between modulation patterns of transmitted and received test signals.

Abstract: An optical transmission link pumped with multiple orders Raman pumps on both ends of the link is disclosed. At least one first-order Raman pump and at least two higher-order Raman pumps are provided on each end for reducing optical power variation of the optical signal along the optical transmission link. Wavelengths and optical power levels of the multiple-order Raman pumps and the additional Raman pump(s) can be selected by computer simulation to lessen the spatial optical power variation of the optical signal.

Abstract: A scalable multicast M×N optical switch (MCS) includes a non-scalable MCS having a plurality of (L+1)×1 selector switches east coupled at one of its L entrance ports to egress ports of the non-scalable MCS, the remaining L?1 entrance ports being coupled to an L*N upgrade ports, where M and N are integers ?2, and L is an integer ?1. This allows the scalable MCS to be cascaded in a daisy-chain fashion, providing scalability from the M common ports to L*M common ports. In another embodiment, the selector switches are integrated into the MCS, providing scalability of common MCS ports.

Abstract: An optical delivery waveguide for a material laser processing system includes a small lens at an output end of the delivery waveguide, transforming laser beam divergence inside the waveguide into a spot size after the lens. By varying the input convergence angle and/or launch angle of the laser beam launched into the waveguide, the output spot size can be continuously varied, thus enabling a continuous and real-time laser spot size adjustment on the workpiece, without having to replace the delivery waveguide or a process head. A divergence of the laser beam can also be adjusted dynamically and in concert with the spot size.

Abstract: A multicast optical switch uses a diffractive bulk optical element, which splits at least one input optical beam into sub-beams, which freely propagate in a medium towards an array of directors, such as MEMS switches, for directing the sub-beams to output ports. Freely propagating optical beams can cross each other without introducing mutual optical loss. The amount of crosstalk is limited by scattering in the optical medium, which can be made virtually non-existent. Therefore, the number of the crossover connections, and consequently the number of inputs and outputs of a multicast optical switch, can be increased substantially without a loss or a crosstalk penalty.

Abstract: An aberration corrector and a method to reducing a spherical aberration are disclosed. The aberration corrector has a radial, rotationally symmetric variation of refractive index including a term varying in proportion to a fourth degree of a distance from the optical axis. Since the spherical aberration causes a wavefront deviation proportional to the fourth degree of distance from the optical axis, the spherical aberration can be reduced by the aberration corrector when its thickness causes the exact amount of the phase delay corresponding to the wavefront deviation, but with an opposite sign.

Abstract: A package for an arcuate planar lightwave circuit (PLC) chip includes a heater plate coupled to a base by a thick and soft support layer. The arcuate PLC is attached to the heater plate by soft adhesive. A hard adhesive is applied to a multi-waveguide end of the arcuate PLC, to additionally strengthen the attachment of the arcuate PLC to the heater plate. The structure allows the mechanical stress due to fiber pull/shock/vibration to be dissipated in the support layer without introducing large wavelength shifts in the arcuate PLC. The support layer also serves as a heat insulator, facilitating uniform heating of the arcuate PLC.

Abstract: A laser diode subassembly is disclosed, in which dichroic reflectors are disposed sequentially one after another forming an array or stack, each reflector having a sequential array index. An array of laser diode emitters is provided, each emitter having a sequential array index. Individual reflectors of the array redirect laser sub-beams from individual laser diode emitters having same array indices, to propagate via dichroic reflectors having higher array indices, so as to form a combined optical beam. A common partial reflector may be used for the laser diode emitters instead of individual wavelength selective reflectors for each laser diode emitter.