摘要:
An instrument including a device, a transducer and a calibration module is disclosed. The device produces a reference time and/or a reference frequency. The transducer converts the reference time and/or the reference frequency to a reference signal. The calibration module adjusts an output signal generated by the instrument and/or a result of a measurement taken by the instrument, based on the reference signal. A system including the instrument and a method of calibrating the instrument are also disclosed.
摘要:
Two or more local-oscillator-equipped instruments connected to a network are disclosed. Among the instruments, one instrument is designated as the master instrument and the rest, slave instruments. A master clock signal generated by the local oscillator of the master instrument is used by the slave instruments, through the network, to discipline their own local oscillators to generate slave clock signals that are synchronized to the master clock signal.In one embodiment, in the slave instrument, the master clock signal from the master instrument is used as a reference to generate slave clock signals. In another embodiment, the phases of the slave clock signals are adjusted to compensate for the phase difference between the slave clock signals and the master clock signal.
摘要:
A sensor head for use with a measurement grating is described. The sensor head comprises: a splitter grating configured to split a light beam into first and second measurement beams; a first retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating; and a second retroreflector configured to retroreflect the first and second measurement beams toward the measurement grating. In one embodiment the second measurement beam is diffracted by the measurement grating to form first and second sub-beams and one of the first and second sub-beams comprises a zeroth order diffraction component and a first order diffraction component. In another embodiment, the first and second sub-beams each comprise a zeroth order diffraction component and a first order diffraction component.
摘要:
A displacement measurement apparatus includes a light source, a splitter grating, a measurement grating, and first a second detector arrays. The splitter grating splits a light beam into first and second measurement channels that each illuminates the measurement grating. The first and second measurement channels split into 0th and 1st order diffraction products at the measurement grating in a first pass and recombine at the measurement grating in a second pass before being measured at the first and second detector arrays.
摘要:
Systems and methods of identifying molecules of polymers such as, for example, a nucleic acid, are described. The method involves centering a bias voltage across a pair of nanoelectrodes separated by a channel that corresponds to one of any of the energy differences between any two internal energy levels of a molecule of interest, and modulating the bias voltage with a modulation waveform while the molecule of interest is in the channel. An electrical signal characteristic of the molecule of interest is derived from the tunneling current between the nanoelectrodes, and the characteristic electrical signal is compared with known values of the signal for chemically-known molecules in order to identify the molecule of interest. Multiple pairs of nano-electrodes may be employed to identify more reliably a single molecule or multiple molecules.
摘要:
A light source system includes a beam source generating a first input beam of light. An anisotropic acousto-optic modulator (AOM) is positioned to receive the first input beam. The AOM includes a plurality of transducers for receiving control signals and generating corresponding acoustic waves that operate on the first input beam to generate first and second output beams with different frequencies and orthogonal linear polarizations. The first and second output beams have a combined optical power that is substantially the same as an optical power of the first input beam for a first input beam with one polarization and for a first input beam with two polarizations.
摘要:
Measurement systems that separate polarization components can use retroreflectors to preserve or transform polarization and avoid unwanted mixing of the polarization components. A suitable retroreflector can include a coated cube corner reflector with retardation plates having a slow axis set at a non-zero angle away from 45° with the directions of linearly polarized component beam. The non-zero angle can be set in situ to minimize polarization mixing in a measurement system. Alternatively, a cube corner reflector with one or more polarization manipulating elements controls the polarization of a reflected beam to preserve or transform the polarization of an incident beam.
摘要:
An apparatus and method for measuring CPT is disclosed. The apparatus includes a quantum absorber that is irradiated by radiation from an electromagnetic radiation source. The quantum absorber includes a material that exhibits CPT. The electromagnetic radiation source generates electromagnetic radiation having first and second CPT-generating frequency components. The first CPT-generating frequency component has a frequency νL−ν, and a first CPT component amplitude. The second CPT generating frequency component has a frequency νL+ν and a second CPT component amplitude. The apparatus also includes a detector for generating a detector signal related to the power of electromagnetic radiation that leaves the quantum absorber. The detector signal exhibits an asymmetry as a function of frequency ν in a frequency range about a frequency ν0. The apparatus includes an asymmetry servo loop that alters one of νL, the first CPT component amplitude, and the second CPT component amplitude to reduce the asymmetry.
摘要:
Systems and methods of identifying molecules of polymers such as, for example, a nucleic acid, are described. The method involves centering a bias voltage across a pair of nano-electrodes separated by a channel that corresponds to one of any of the energy differences between any two internal energy levels of a molecule of interest, and modulating the bias voltage with a modulation waveform while the molecule of interest is in the channel. An electrical signal characteristic of the molecule of interest is derived from the tunneling current between the nano-electrodes, and the characteristic electrical signal is compared with known values of the signal for chemically-known molecules in order to identify the molecule of interest. Multiple pairs of nano-electrodes may be employed to identify more reliably a single molecule or multiple molecules.
摘要:
A semiconductor optical amplifier (SOA) apparatus and related methods are described. The SOA comprises a signal waveguide for guiding an optical signal along a signal path, and further comprises one or more laser cavities having a gain medium lying outside the signal waveguide, the gain medium being sufficiently close to the signal waveguide such that, when the gain medium is pumped with an excitation current, the optical signal traveling down the signal waveguide is amplified by an evanescent coupling effect with the laser cavity. When the gain medium is sufficiently pumped to cause lasing action in the laser cavity, gain-clamped amplification of the optical signal is achieved. Additional features relating to segmented laser cavities, separate pumping of laser cavity segments, DFB/DBR gratings, current profiling to improve ASE noise performance, coupled-cavity lasers, avoidance of injection locking effects, manipulation of gain curve peaks, integration with a tunable vertical cavity coupler, integration with a photodetector, integration with an RZ signal modulator, and other described features may be used with the evanescent coupling case or with an SOA having a laser cavity gain medium that is coextensive with the gain medium of the signal waveguide.