摘要:
A measurement system has a modulated laser source that illuminates a target within the measurement system. The modulated laser source has a first coherence length in an unmodulated state, and a second coherence length in a modulated state that is shorter than the first coherence length. The measurement system includes a detector that receives a deflected signal from the target and provides a detected signal having a signal component and a drift component, wherein the drift component is lower in the modulated state than in the unmodulated state of the modulated laser source.
摘要:
A system and method of using a refractive index sensor to determine a characteristic of a sample. The operation of the system and method allow for determining a change in a bulk index of the sample, and an amount of sample adsorption, using a reflected beam from an interface of the sensor. An embodiment of a system and method further provide for identifying changes in incident angles determine from reflective measurement data of the sensor, in combination with different proportionality constants of the refractive index sensor to determine a characteristic of the sample.
摘要:
A computer cursor control device includes (1) a light source generating light directed toward a stationary surface, (2) an optional phase modulator, (3) an optional function generator causing the phase modulator to periodically phase shift the light, and (4) a signal processor determining a direction in which the device is moving from a beat frequency or an asymmetry in the light intensity. Another computer cursor control device includes (1) an optical element combining reference and measurement beams to form a heterodyned beam, (2) a phase modulator located in an optical path of the reference beam or the measurement beam, (3) a function generator causing the phase modulator to phase shift the reference beam, and (4) a signal processor determining a direction in which the device is moving from a beat frequency of the heterodyned beam.
摘要:
A nonlinear filtering system determines the duration of a designated event in an SPR sensorgram, selects a filter length based on the determined duration of the designated event in the SPR sensorgram, and applies a nonlinear filter, having the selected filter length to the SPR sensorgram, to establish an output signal.
摘要:
A system, method, and device for tracking motion across a surface by creating an interference pattern by reflecting light from the surface. There is produced, as a result of sensor moving across the surface, at least one signal pattern corresponding to a detection of a dimension of the interference pattern. This detected dimension is associated with an assumed dimensional value to determine a distance traveled by the sensor.
摘要:
A system for characterizing optical properties of a device under test (DUT) uses an expanded local oscillator signal to perform multiple parallel interferometric measurements. In one system, the expanded local oscillator signal is optically connected to a lens array. The lens array focuses the expanded swept local oscillator signal into multiple beams. The multiple beams are then used in multiple parallel interferometric measurements. The multiple beams may be used as the reference beams or applied to the DUT and used as the test beams depending on the application. The test beams and reference beams are combined to perform the interferometric measurements. In another system, a portion of the expanded local oscillator signal is applied directly to a DUT as the test beam while another portion of the expanded local oscillator signal is used for the reference beam.
摘要:
A multiplexed optical detector includes a set of optical sensors coupled to a multiplexer that maps subsets of the optical sensors to at least one multiplexed output provided by the multiplexer. The subsets of optical sensors are configurable according to addresses that are provided to the multiplexer.
摘要:
Characterizing active and passive properties of an optical device involves applying a local oscillator signal to a device under test (DUT) and providing a portion of the local oscillator signal (referred to as the reference local oscillator signal) directly to the an optical analyzer. Providing the reference local oscillator signal to the optical analyzer enables interferometric measurements associated with the DUT to be obtained along with direct measurements, where the interferometric measurements result from combining the portion of the local oscillator signal that is applied to the DUT with the reference local oscillator signal. The interferometric measurements are used to characterize passive properties of the DUT while the direct measurements are used to characterize active properties of the DUT.
摘要:
A measurement system, a chaotic lock-in amplifier, and methods use chaotic lock-in amplification to measure a stimulus response from one or more of a device under test, a sample under test and a system under test. The measurement system includes a chaotic reference source, a chaotic excitation source and a chaotic lock-in amplifier to facilitate detection of a chaotic response signal from the respective item(s) under test. A chaotic lock-in amplifier includes an inverse system that removes a chaotic component from the chaotic response signal. A method of measuring a response to a stimulation includes using the chaotic reference signal to achieve chaotic lock-in amplification that preferentially removes a chaotic component from the chaotic response signal.
摘要:
Optical phase detection includes generating a first lightwave having a first polarization and a second lightwave having a polarization that is offset from the first polarization, and imposing a relative delay between the first and second lightwaves. The relative delay causes a frequency offset between the lightwaves as wavelength is tuned over a designated wavelength range. Directing the first and second lightwaves to a target provides a third lightwave and a fourth lightwave. A polarization component of the third lightwave and a polarization component of the fourth lightwave are detected to provide a detected signal at the frequency offset. The optical phase detection then includes extracting a phase difference, induced by the target, between the polarization components of the third and the fourth lightwaves.