Abstract: Techniques for producing higher fidelity interferometer measurements by reducing sensitivity to spurious sources include reducing the coherence length of an electromagnetic beam. In addition, multiple surfaces within an optical system may be measured by electronically tuning the position of a coherence plane along the optical paths of an interferometer. A phase modulator is used in conjunction with a long coherence length electromagnetic source to generate beams for each leg of an interferometer. Providing a controlled broadband RF signal to the phase modulator increases the bandwidth of the beam and thereby reduces the coherence length of the beam. This reduces the spurious contributions to the output interference fringes from undesired surfaces along the beam path.

Abstract: Techniques for producing higher fidelity interferometer measurements by reducing sensitivity to spurious sources include reducing the coherence length of an electromagnetic beam. In addition, multiple surfaces within an optical system may be measured by electronically tuning the position of a coherence plane along the optical paths of an interferometer. A phase modulator is used in conjunction with a long coherence length electromagnetic source to generate beams for each leg of an interferometer. Providing a controlled broadband RF signal to the phase modulator increases the bandwidth of the beam and thereby reduces the coherence length of the beam. This reduces the spurious contributions to the output interference fringes from undesired surfaces along the beam path.

Abstract: A method and apparatus for an analog to digital converter with dynamically reconfigurable conversion resolution. The analog to digital converter comprises a sample and hold circuit, a controller, and a single, one-bit converter stage. The sample and hold circuit holds an input analog signal to form a captured analog signal. The controller determines a number of digital output bits required to generate digital output at a user defined conversion resolution. The one-bit converter stage processes an instance of a captured analog signal to generate an output bit. The controller iteratively processes a residue voltage through the one-bit converter stage a number of times required to generate the number of digital output bits to form a digital output with the user defined conversion resolution.

Abstract: A method and apparatus for a focal plane array with serial, variable bit width analog to digital converter. The focal plane array includes a plurality of pixels and a dynamically reconfigurable analog to digital converter. The controller determines a number of digital output bits required to generate digital output at a selected conversion resolution. A sample and hold circuit holds an analog voltage from a pixel to form a captured analog signal. A one-bit converter stage processes an instance of a captured analog signal to generate an output bit. The controller iteratively processes a residue voltage through the one-bit converter stage a number of times required to generate the number of digital output bits to form a digital output with the user defined conversion resolution.

Abstract: A method and apparatus for a focal plane array with serial, variable bit width analog to digital converter. The focal plane array includes a plurality of pixels and a dynamically reconfigurable analog to digital converter. The controller determines a number of digital output bits required to generate digital output at a selected conversion resolution. A sample and hold circuit holds an analog voltage from a pixel to form a captured analog signal. A one-bit converter stage processes an instance of a captured analog signal to generate an output bit. The controller iteratively processes a residue voltage through the one-bit converter stage a number of times required to generate the number of digital output bits to form a digital output with the user defined conversion resolution.

Abstract: A method and apparatus for an analog to digital converter with dynamically reconfigurable conversion resolution. The analog to digital converter comprises a sample and hold circuit, a controller, and a single, one-bit converter stage. The sample and hold circuit holds an input analog signal to form a captured analog signal. The controller determines a number of digital output bits required to generate digital output at a user defined conversion resolution. The one-bit converter stage processes an instance of a captured analog signal to generate an output bit. The controller iteratively processes a residue voltage through the one-bit converter stage a number of times required to generate the number of digital output bits to form a digital output with the user defined conversion resolution.

Abstract: Techniques for producing higher fidelity interferometer measurements by reducing sensitivity to spurious sources include reducing the coherence length of an electromagnetic beam. In addition, multiple surfaces within an optical system may be measured by electronically tuning the position of a coherence plane along the optical paths of an interferometer. A phase modulator is used in conjunction with a long coherence length electromagnetic source to generate beams for each leg of an interferometer. Providing a controlled broadband RF signal to the phase modulator increases the bandwidth of the beam and thereby reduces the coherence length of the beam. This reduces the spurious contributions to the output interference fringes from undesired surfaces along the beam path.