Abstract: A vacuum chamber deposits thin films on a substrate by sputtering a target. The beam of atoms or ions from the target is partially blocked by a shadow or adjustable uniformity mask, reducing the deposition rate onto the substrate. The adjustable uniformity mask has several adjustable fingers. The fingers extend or retract to enlarge or reduce the size of the mask. Each finger covers a different annular region or radius of the substrate. The deposition rate at different substrate radii is thus adjustable by the fingers. Several optical beams monitor the film transmittance at different substrate radii. A transmittance profile is continually generated during deposition. As deposition proceeds, radii with a thicker film have their fingers extended to reduce their deposition rate, producing a more uniform film thickness across all radii. Motors extend or retract the individual fingers.

Abstract: Optical logic gates are constructed from Mach-Zehnder Interferometer (MZI) optical circuits. A multi-mode interference (MMI) splitter divides a continuous-wave input into two branches of the interferometer. Each branch has a semiconductor optical amplifier (SOA). When a logic input having a logic-high power level is applied to one of the SOA's, cross-phase modulation occurs in the SOA. The phase shift increases through the SOA. The branch coupled to the logic input has a relative phase shift of &pgr; compared with the other branch. When two branches with the &pgr; phase difference are combined, destructive interference occurs, producing a logic low. An MMI combiner or an equivalent phase shifter is used to combine the two branches. The MMI splitter adds a phase shift of &pgr;/2 to the upper branch but not to the lower branch, while the MMI combiner also adds &pgr;/2 shifts.

Abstract: Optical logic gates are constructed from Mach-Zehnder interferometer (MZI) optical circuits. A multi-mode interference (MMI) splitter divides a continuous-wave input into two branches of the interferometer. Each branch has a semiconductor optical amplifier (SOA). When a logic input having a logic-high power level is applied to one of the SOA's, cross-phase modulation occurs in the SOA. The phase shift increases through the SOA. The branch coupled to the logic input has a relative phase shift of &pgr; compared with the other branch. When two branches with the &pgr; phase difference are combined, destructive interference occurs, producing a logic low. An MMI combiner or an equivalent phase shifter is used to combine the two branches. The MMI splitter adds a phase shift of &pgr;/2 to the upper branch but not to the lower branch, while the MMI combiner also adds &pgr;/2 shifts.

Abstract: A novel semiconductor optical amplifier (SOA) can operate as an optical inverter as well as a power-restoring device. Together, an optical-OR and the optical inverter can provide a wide variety of high speed optical logic gates and functions. The optical inverter uses cross-gain modulation (XGM) to invert a modulated signal on a first input, to produce an inverted output. The inverse of the modulation is transferred from a first wavelength of the modulated first input to a second wavelength of a continuous-wave second input. A filter can then block the first wavelength, allowing the inversely-modulated second wavelength to be output as the inverted output. The first and second wavelengths are swapped in alternate inverters in a logic path. The Y-junction can be implemented as a Multi-Mode Interference (MMI) device.

Abstract: A vacuum chamber deposits thin films on a substrate by sputtering a target. The beam of atoms or ions from the target is partially blocked by a shadow or adjustable uniformity mask, reducing the deposition rate onto the substrate. The adjustable uniformity mask has several adjustable fingers. The fingers extend or retract to enlarge or reduce the size of the mask. Each finger covers a different annular region or radius of the substrate. The deposition rate at different substrate radii is thus adjustable by the fingers. Several optical beams monitor the film transmittance at different substrate radii. A transmittance profile is continually generated during deposition. As deposition proceeds, radii with a thicker film have their fingers extended to reduce their deposition rate, producing a more uniform film thickness across all radii. Motors extend or retract the individual fingers.