Patent application number | Description | Published |
20080225262 | Displacement Measurement System - 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 0 | 09-18-2008 |
20080304079 | DISPLACEMENT MEASUREMENT SENSOR HEAD AND SYSTEM HAVING MEASUREMENT SUB-BEAMS COMPRISING ZEROTH ORDER AND FIRST ORDER DIFFRACTION COMPONENTS - 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. | 12-11-2008 |
20090135430 | Systems and Methods for Reducing Nonlinearity in an Interferometer - A system for measuring electromagnetic interference, the system comprising: a plane mirror interferometer receiving a first electromagnetic beam and a second electromagnetic beam having a same linear polarization, each of the first and second electromagnetic beams transmitted on separate paths such that the beams are non-overlapping until immediately before detection of the beams, wherein the interferometer includes: a reference surface and a measurement surface, the reference surface reflecting the first beam, and the measurement surface reflecting the second beam; and a polarization beam splitter, wherein the first and second beams enter the polarization beam splitter at a same facet of the polarization beam splitter. | 05-28-2009 |
20090296760 | Optical Pumping Apparatus and Method to Reduce AC Stark Shift in Atomic Frequency Standards - An optical pumping atomic frequency apparatus for producing an oscillation signal with a stable frequency comprises a cell containing atomic particles of a quantum absorber material whose atomic particles have two clock transition states and first and second excited states. A static bias magnetic field is provided at the cell. A first electromagnetic (EM) field is provided to the cell, to excite transitions between at least one of the clock transition states and at least one of the first and second excited states due to absorption of the first EM field by the atomic particles in the at least one of the clock transition states, in order to alter the relative population of the atomic particles. A second EM field is applied to the cell, to induce transitions between the two clock transition states, so that the absorption of the first EM field by the atomic particles increases. Absorption of the first EM field is detected. The frequency spectrum of the first and second EM fields are controlled; so that the frequency of the output oscillating signal is related to the clock transition frequency. The interactions between the atomic particles and the first EM field cause a light shift as a function of the intensity and the frequency of the first EM field, the light shift having a characteristic curve. The light shift has an absolute value which is related to the frequency and polarization of the first EM field, and the frequency and polarization are chosen to reduce the absolute value of the light shift. The light shift curve has a slope at the frequency which corresponds with an energy difference between the at least one of the clock states and the at least one of the first and second excited states, the slope thereat related to the chemical composition and partial pressure of the buffer gas in the cell. The composition and pressure of the buffer gas reduce the absolute value of the slope of the light shift curve of the clock transition frequency to approximately zero. | 12-03-2009 |
20090316740 | Light Source That Utilizes Small Footprint Reference Gas Cells for Multiple Laser Frequency Stabilization - A light source and the method for operating the same are disclosed. The light source includes first and second lasers, and first and second wavelength control assemblies. The lasers emit first and second light beams, respectively, at wavelengths that are determined by first and second wavelength control signals. First and second beam splitters split the first and second light beams, respectively, to create first and second sampling light beams. The first and second wavelength control assemblies receive sampling light beams and generate the first and second wavelength control signals such that the wavelengths of the first and second light beams differ by no more than a predetermined amount. The first and second wavelength control assemblies each include an absorption cell having a gas that has an optical absorption that varies with the wavelength of the first and second sampling light beams at wavelengths around the output wavelength of the light source. | 12-24-2009 |
20100148757 | METHOD OF CALIBRATING AN INSTRUMENT, A SELF-CALIBRATING INSTRUMENT AND A SYSTEM INCLUDING THE INSTRUMENT - 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. | 06-17-2010 |
20100150288 | Synchronization of Low Noise Local Oscillator using Network Connection - 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. | 06-17-2010 |
20130258343 | METHOD AND APPARATUS TO IMPROVE SIGNAL-TO-NOISE RATIO OF FT-IR SPECTROMETERS USING PULSED LIGHT SOURCE - An optical spectroscopy method and apparatus increases signal to noise ratio of detected signals. Sample light passed through a sample includes attenuated light pulses and characteristic light located between the attenuated light pulses, the characteristic light formed by interaction between light pulses incident the sample and sample molecules. The attenuated light pulses are substantially removed from the sample light emerging from the sample prior to detection, to increase signal to noise ratio of the detected signal. | 10-03-2013 |
20150062586 | SYSTEM FOR PERFORMING OPTICAL SPECTROSCOPY INCLUDING INTERFEROMETER - A system for performing optical spectroscopy measurements includes a light source for generating an input optical beam and an interferometer. The interferometer includes a beam splitter that splits the input optical beam into first and second light beams; a first light path that directs the first light beam through a sample containing an analyte to a first output port; and a second light path that directs the second light beam to the first output port. At least one of the first and second light paths adjusts a relative phase of a corresponding one of the first and second light beams, so that the first and second light beams are out of phase at the first output port, substantially canceling background light and outputting sample light corresponding to a portion of the first light signal absorbed by the sample in the sample cell. A detection system detects the output sample light. | 03-05-2015 |