Abstract: A first image may be obtained using locked (relative) phases. A second image may be obtained using unlocked (e.g., randomized) phases. Data of the second image may be subtracted from data of the first image. The result may then undergo further processing, if desired, e.g., to further enhance the resulting image.

Abstract: An optical modulation apparatus for modulating an electromagnetic (e.g., radio frequency (RF)) signal onto an optical carrier signal may be arranged to feed back at least a portion of the optical carrier signal, while excluding first-order sidebands, which may help increase modulation efficiency and improve output power, while retaining high modulation bandwidth. Such arrangements may be implemented, for example, using a Fabry-Perot resonator or a ring resonator in combination with a Mach-Zehnder interferometer or a Michelson interferometer.

Abstract: An optical modulation apparatus for modulating an electromagnetic (e.g., radio frequency (RF)) signal onto an optical carrier signal may use carrier recycling to increase modulation efficiency. Such an arrangement may be implemented, e.g., using a Fabry-Perot topology and/or using a travelling-wave modulator.

Abstract: An optical modulation apparatus for modulating an electromagnetic (e.g., radio frequency (RF)) signal onto an optical carrier signal may be arranged to feed back at least a portion of the optical carrier signal, while excluding first-order sidebands, which may help increase modulation efficiency and improve output power, while retaining high modulation bandwidth. Such arrangements may be implemented, for example, using a Fabry-Perot resonator or a ring resonator in combination with a Mach-Zehnder interferometer or a Michelson interferometer.

Abstract: An apparatus and method may be used to create images, e.g., three-dimensional images, based on received radio-frequency (RP), e.g., millimeter wave, signals carrying image data. The RF signals may be modulated onto optical carrier signals, and the resulting modulated optical signals may be cross-correlated. The resulting cross-correlations may be used to extract image data that may be used to generate three-dimensional images.

Abstract: A first image may be obtained using locked (relative) phases. A second image may be obtained using unlocked (e.g., randomized) phases. Data of the second image may be subtracted from data of the first image. The result may then undergo further processing, if desired, e.g., to further enhance the resulting image.

Abstract: A system and method for locking the relative phase of multiple coherent optical signals, which compensates for optical phase changes induced by vibration or thermal changes in the environment.

Abstract: A system and method for locking the relative phase of multiple coherent optical signals, which compensates for optical phase changes induced by vibration or thermal changes in the environment.

Abstract: A system and method for locking the relative phase of multiple coherent optical signals, which compensates for optical phase changes induced by vibration or thermal changes in the environment.

Abstract: A system and method for locking the relative phase of multiple coherent optical signals, which compensates for optical phase changes induced by vibration or thermal changes in the environment.

Abstract: The present invention is an efficient method for the fabrication of three-dimensional structures in GaAs-based materials. The method is particularly suitable for the realization of 3D photonic crystals. The method relies on the observation that the oxidation rate of Ga1-xA1xAs in water-vapor atmosphere is a strong function of the aluminum content in the alloy. Thus, a stack of Ga1-xA1xAs layers with varying concentration of A1 is grown on GaAs substrate. The top surface is patterned with an array of holes, which are then transferred to the underlying layers by dry etching. Subjecting the so-prepared structure to oxidation in water vapor atmosphere at an elevated temperature results in lateral oxidation of the material exposed by the etched holes. The lateral oxidation depth depends on aluminum content in a particular layer. The oxide is then removed by an aqueous solution of hydrofluoric acid and a three-dimensional array of voids ensues.

Abstract: Methods and apparatus for detecting waves are disclosed. The waves are detected by modulating an optical carrier signal having a carrier signal frequency component at a carrier frequency with wave signals at one or more detection frequencies, optically removing the carrier signal frequency component from the modulated optical carrier signal, and detecting an energy level of the modulated optical carrier signal after removal of the carrier signal frequency component, the energy level indicative of the presence of the wave signals.