Abstract: A spatial light modulator for use in a photolithography system includes light modulation elements configured to photolithographically transfer an image onto a substrate using an optical oversampling technique to reduce defects in the transferred image. A first set of the light modulation elements is operable to photolithographically transfer a portion of the image onto an area of a substrate, and a second set of the light modulation elements is operable to photolithographically transfer the portion of the image onto the area of the substrate. The spatial light modulator further includes memory elements in communication with respective light modulation elements for storing data representing the portion of the image.

Abstract: A wavelength selective switching device and method for selectively transmitting optical signals based on wavelength utilizes diffraction to spatially separate the optical signals of different wavelengths such that the optical signal of a selected wavelength can be selectively transmitted. The wavelength selective switching device selectively rotates the polarization components of the optical signals such that the polarization states of the polarization components are the same in both incoming and outgoing directions at the diffraction grating. Thus, a diffraction grating with a high grating line frequency (e.g. greater than 900 grating lines per mm for signals in the 1550 nm wavelength range) can be used for diffracting the polarization components of the optical signals in both the incoming and outgoing directions.

Abstract: A method of enhancing wavelength tuning performance in an external cavity laser includes providing a diffractive focusing element, emitting light into the cavity of the laser at a range of angles relative to an optical axis of the cavity, and diffractively focusing the light back onto the optical axis at a wavelength-dependent focal distance using the diffractive focusing element. The method further includes confining the diffractive focusing to a high dispersivity portion of the diffractive focusing element. In various embodiments, the confining may include offsetting the diffractive focusing element radially relative to the optical axis, or selectively blocking a portion of the light emitted into the cavity at emission angles less than a threshold emission angle.

Abstract: A polarization control device, comprising: a liquid crystal device containing a liquid crystal material with an optical anisostropy with substantially homeotropically aligned molecules when in a neutral electrical field state; a plurality of electrodes for applying an electrical field to change an orientation of the molecules of the liquid crystal material from their alignment in the neutral electrical filed state; a circuit for applying a voltage to the electrodes; and an optical system for directing light through the liquid crystal material.

Abstract: Methods for performing time-domain equalization of an information signal represented by an optical signal are provided. A representative method includes: receiving the optical signal; optically splitting the optical signal into beams; optically delaying at least one of the beams; detecting a plurality of the beams to generate respective electrical signal components; and combining a plurality of the electrical signal components to generate an electrical output signal representing the information signal. Systems and other methods also are provided.

Abstract: A gas-fired construction heater which meets the applicable ANSI Standard and operates to supply heated air separately from products of combustion. The products of combustion are permitted to contain no more than a specified percent of carbon monoxide when uncontrolled heater operating conditions are within predetermined ranges. The uncontrolled operating conditions include variations in input rate and supply voltage. A combustion chamber produces the products of combustion and has primary and secondary combustion zones. A heat exchanger receives the products of combustion and transfers heat therefrom to fresh air to be heated. The chamber and the heat exchanger define a tertiary combustion zone. Inlets supply a separate natural combustion draft to each of the primary and tertiary combustion zones. The inlets include a first and a third fixed-area inlet for respectively supplying the separate natural drafts to the primary and tertiary combustion zones.