Abstract: An agile optical sensor based on spectrally agile heterodyne optical interferometric confocal microscopy implemented via an ultra-stable in-line acousto-optic tunable filter (AOTF) based interferometer using double anisotropic acousto-optic Bragg diffraction. One embodiment uses a tunable laser as the light source while other embodiments use a broadband source or a fixed wavelength laser as the source. One embodiment uses anisotropic diffractions in an AOTF to generate two near-collinear orthogonal linear polarization and slightly displaced beams that both pass via a test sample to deliver highly sensitive sample birefringence or material optical retardation measurements. A spherical lens is used to form focused spots for high resolution spatial sampling of the test object. The laser and AOTF tuning allows birefringence measurements taken at different wavelengths, one at a time.

Abstract: An agile optical beam profiler using a two-dimensional small tilt digital micromirror device/chip, a translation stage, and single photodetector or pair of photodetectors. A method of profiling an optical beam includes positioning a programmable spatial light modulator in an incident optical beam and sequentially moving the spatial light modulator to at least one position in a first planar direction in a displacement increment less than a pixel width of the spatial light modulator. The method also includes directing respective portions of the optical beam to a photodetector at each position of the spatial light modulator. The method may also include calibrating the photodetectors by directing a portion of the beam to the photodetector, then directing the entire beam, or a remaining portion of the beam, to the photodetector, and normalizing the detected power of the portion with the detected power of the entire beam, or remaining portion, respectively.

Abstract: Electronically agile optical filtering modules for equalizing light propagation differences in at least two spaced optical beam pathways in the modules. The modules use optical polarization rotation devices that may include acousto-optic tunable filter (AOTF) devices, liquid crystal devices, and magneto-optic devices. Such devices may be subject to polarization dispersion losses (PDL) and polarization mode dispersion (PMD) that may be different for when light travel along different light paths through the device. By redirecting light beams back along a different bi-directional path through the devices which may exhibit non-uniform performance across orthogonal polarizations, PDL and PMD may be reduced.

Abstract: An optical beam profiler using a spatial light modulator and photodetector. In an embodiment, the spatial light modulator is a two-dimensional (2-D) small tilt digital micromirror device. The profiler features fast speed, digital controls, low polarization sensitivity, and high measurement repeatability. The 2-D multi-pixel device-based profiler allows the use of several beam profile measurement concepts including moving knife edge, scanning slit, moving pinhole, variable aperture, and 2-D photodiode array. The proposed digital optical beam profiler can be implemented with any type of digitally operated 2-D spatial light modulator device such as using liquid crystals, magneto-optics, multiple quantum wells, electro-optic polymers, and photonic crystals.

Abstract: Unique multi-diffraction structures using electronically controlled Bragg diffraction devices such as acousto-optic (AO) devices to accomplish optical beam attenuation control functions. These variable optical attenuator (VOA) modules can be fully inertialess as they can use electronically programmable sub-microsecond speed AO devices to implement optical gain controls. These VOAs deliver desirable capabilities in one optically reversible unit, making high dynamic range, low loss, high power handling, ultra-fast, high optical isolation, broadband operation, self-aligning robust modules. These VOAs can be made essentially independent of the optical polarization of the incident light by the use of a unique fixed waveplate compensation technique within the VOA configuration that suppresses polarization dependent loss. Broadband gain control operation over several wavelengths can be achieved by controlling the frequency and electrical drive power of the chosen frequencies feeding the acousto-optic devices.

Abstract: Multi-wavelength fiber-optic processors based on a fault-tolerant scheme using a macro-pixel to control an optical beam are described. The macro-pixel system uses multiple device pixels per beam to provide a robust digital technique for amplitude control and routing, enabling a module with high optical beam alignment tolerance and resistance to catastropic failure. In one embodiment, the macropixel is implemented via small tilt micromirrors fabricated via optical microelectromechanical systems (MEMS) technology. The system includes fault tolerant fiber-optic processors that can implement add-drop wavelength routing, optical power level conditioning per wavelength, 2×2 optical crossconnects, and 1×N and M×N type broadcast-gain controlled switches. The system can simultaneously and independently implement optical power conditioning and wavelength routing for any wavelength channel.

Abstract: High speed optical scanner systems and methods using optical multiplexing of wavelengths and spatial codes. In one form, a wavelength multiplexed optical scanner (W-MOS) is disclosed, wherein tuning the wavelength or selection of wavelength accomplishes a high speed, no-moving, parts scanner coupled with a wavelength dispersive element, such as a grating or a thin-film interference filter. In another form, a W-MOS employs beam expansion optics and a freespace-coupled wavelength dispersive element. In another embodiment, the invention includes a fiber-based W-MOS using an optical fiber coupled with a fiber-based wavelength division multiplexer (WDM) device to form a spatially distributed scanner for wide angular coverage in three-dimensional beam scanning. The invention also includes a code multiplexed optical scanner (C-MOS) that uses the principle of holography and spatial code multiple access optical communications.

Abstract: A high resolution, fault tolerant, variable optical attenuator and polarizer module for fiber optical beam control using parallel, serial, and serial-parallel optical control architectures. The module uses mixed control modes to control a macropixel array and includes spatially multiplexed processing techniques. The macropixel array consists of an array of individually controlled pixels, such as a microelectromechanical system (MEMS) mirror array, where each pixel has a specific addressable location in the array, and each pixel can have a unique size, shape and electrical or optical drive format. The module can provide amplitude, routing, and polarization control of an input optical beam. In an embodiment, the module can control the gain of a light beam in fiber optical systems coupled to lenses. In another embodiment, the modules can be cascaded to form a high-resolution fiber optic attenuator.

Abstract: This invention pertains to a basic multi-technology application of cascaded beam-formers. A dual MEMS-EO technology platform method involving a two axis deflection micro-mirror cascaded with a three dimensional electro-optical beam-former such as a multi pixel liquid crystal device forms a powerful reflective control site for an incident beam, thereby inherently providing a robust beam control with both coarse and fine beam control capabilities in three dimensions. The electrically controlled two axis micro-mirror is excellent in providing the large angular beam deflections, while the liquid crystal device provides excellent small-beam deflections. This leads to a mechanically robust beam control module. A multipixel MEMS mirror device option coupled with the EO device can also provide simultaneous multi-beam generation capability. Furthermore, use of macro-pixels for both the MEMS and EO devices provides resistance to single pixel dependent catastrophic failure for the overall module.

Abstract: A fiber-optic switch based on a unique retro-reflection scheme is used to create a 2×2 switch having two fiber-optic circulators and two polarization rotation devices. Passive and active noise filtering techniques maintain the high performance of the switch even when the polarization rotation devices have poor performance. The switch also has the advantage of zero relative time delay between two channels for any of two switch settings making it appropriate for cascading switching stages. The preferred embodiment of the 2×2 optical switch also has a simple design in terms of alignment since only two optical fibers need to be aligned with each other. The switch is also scalable to form N 2×2 optical switch modules for use in add/drop, N-wavelength, multiple fiber-optic networks where its novel retro-reflective characteristic allows the use of half of the required wavelength multiplexers/demultiplexers in the system compared to a transmissive switch add/drop filter.