An alignment method in which light is diffracted from a mask grating to a wafer grating and back through the mask grating to produce a set of output diffraction orders. The intensity of the zeroth output order is monitored and the mask is translated and rotated within the plane containing the mask to align the mask with the wafer. Alignment occurs when the intensity of the zeroth output order is at an extremum. The distance between the mask and wafer is also adjusted to extremize the intensity o...

The wavelength of an optical pump beam is down converted to a longer wavelength in a Raman active gaseous medium by stimulated Raman scattering. The Raman active gaseous medium is contained in the space between a pair of optical reflectors of an optical resonator of the type for producing a focus of the optical beam energy at a point intermediate the length of the resonator within the Raman active medium to enhance conversion of pump energy into the output longer wavelength of the Stokes wave. T...

A bilithic laser resonator having a first block separated from a second block by a gap that can be adjusted to tune the wavelength of the laser. At least one of these blocks consists of a material that is capable of lasing and at least one of these blocks consists of a material that is capable of producing Faraday rotation of an optical beam.

Optical waveguide systems and methods are described. In one aspect, a display system includes a planar acoustic cavity having a fundamental resonant acoustic mode. The acoustic cavity includes an array of optical waveguides and an array of acoustic transducers. Each of the optical waveguides includes a respective cladding surrounding a liquid-filled core. The array of acoustic transducers is operable to generate acoustic waves that propagate in the acoustic cavity across the cores of the optical...

An apparatus for optically shifting the frequency of an input signal beam includes a first Raman medium that receives an input signal beam, a first pump beam, and a first reference beam to responsively generate an intermediate signal beam comprising a Raman sideband of the first Raman medium. A second Raman medium is optically coupled in series with the first Raman medium. The second Raman medium receives the intermediate signal beam, a second pump beam, and a second reference beam to responsive...

Wavelength tunable light sources and methods of operating the same are described. In one aspect, a wavelength tunable light source includes a resonant light path, an optical gain medium, an optical grating, a first acousto-optic deflector, and a second acousto-optic deflector. In another aspect, a light source has a resonant light path containing first and second acousto-optic devices for tuning an output light beam over a specified frequency range with an output wavelength profile. The first ac...

An external cavity laser is formed by feeding back light from a laser through two or more acoustooptic tuneable filters back to the laser. The Doppler shifts introduced by the filters do not entirely cancel. The net Doppler shift caused by the filters is continuously tuned to cause the bandpass of the filter to follow the shifting resonating frequency of the laser to prevent mode hopping.

An electrically tunable optical oscillator. An acoustooptically tunable filter is located in a feedback path of an optical oscillator. The filter non-collinearly diffracts the light signal to selectively tune the oscillator. In one embodiment the light signal passes twice through a single filter in a single transit around the feedback path. In another embodiment the light passes through a pair of filters which are arranged such that any frequency shift created by one is cancelled by the other.

An imaging device having a lens focusing light from a selected scene within an optical footprint, and a substrate including a primary array and at least one navigation array which are positioned within the optical footprint. The primary array acquires a desired image of a portion of the selected scene during an integration period and the at least one navigation array acquires a series of images during the integration period, including a first and a second image having common features from the se...

The CRCSEL comprises a single-mode optical gain structure and an optically-resonant cavity. The single-mode optical gain structure is structured to generate excitation light having a wavelength and a direction. The optically-resonant cavity is optically coupled to the single-mode optical gain structure and is structured to emit an output light beam in a direction substantially orthogonal to the excitation light. The change in light direction provided by the optically-resonant cavity enables the ...