4 results about "Echelle grating" patented technology

An ophthalmic lens defining an optical axis may include a plurality of annular regions extending in a radial direction away from the optical axis, including a corresponding plurality of echelle gratings, where the plurality of echelle gratings form echelle grating profiles, where each echelle grating profile includes a step profile, where the plurality of echelle gratings form a plurality of annular regions extending in a radial direction away from the optical axis. Each echelette grating includes a step, where, for each step, there are M phase shift units arranged vertically, where M is an integer, where each phase shift unit has a phase height configured to shift a phase of a reference light frequency by about N2 [pi], where N is an integer, and where the step profile forms an irregular step.

Systems and methods for generating multiple mutually variant wavelengths of coherent radiation for three-dimensional imaging of a physical object, such as a tooth, are disclosed. A single radiation source, such as a laser diode, emits coherent electromagnetic radiation. A highly dispersive optical element, such as an echelle diffraction grating, separates radiation having specific wavelengths from the emitted spectrum into distinct beams. Optical components, such as optical masks, mirrors, and lenses, select and orient desired beams to illuminate the object. Small changes in drive current or heatsink temperature of the radiation source similarly affect all wavelengths of the emitted spectrum, so the relative wavelength differences of the desired beams of radiation remain constant. This wavelength stability is useful for synthetic wavelength generation for digital holography and minimizes errors in object shape profile measurements at various scales. Use of a single radiation source also reduces system cost and complexity.

This invention discloses a mid-step grating spectrometer based on the principle of cross-dispersion and its fabrication method. The spectrometer includes a principal dispersive element, a transverse dispersive element, an area array detector, an optical fiber, and a slit. The principal dispersive element is a mid-step curved grating; the transverse dispersive element is a small-step curved grating. The mid-step curved grating and the small-step curved grating are used in combination to achieve spectral dispersion and point-to-point aberration elimination imaging. The area array detector is placed in the direction of the emitted light; the optical fiber is used to emit the light to be measured; the slit is located after the optical fiber and acts as an aperture stop. This invention uses a mid-step curved grating and a small-step curved grating to perform cross-dispersion, eliminating the need for collimating and focusing mirrors in traditional structures. The structure is compact, and high-resolution detection can be achieved, solving the problems of large number of components, high cost, and complex assembly in traditional cross-dispersion mid-step grating structures.

The application discloses a kind of high-resolution fiber spectrometer asynchronous calibration observation optimization method and system, belong to astronomical spectral observation technical field, it is applied to the high-resolution fiber echelle grating spectrometer of ThAr lamp single fiber asynchronous calibration mode.The application is deployed high-precision temperature and humidity and air pressure sensor in the spectrograph heat preservation shell, real-time acquisition optical system operating environment parameter, constructs linear correlation model of temperature and humidity, air pressure and wavelength drift based on 12 months measured data, wavelength calibration data in observation process is calculated in real time by environmental data in combination with model, optimize asynchronous calibration observation process, omit the original process frequent calibration lamp observation, mode switching and additional background observation link.It is proved by measurement, the application guarantees 0.0144mÅ wavelength calibration precision, improves the throughput of spectrometer data 28.57%, improves astronomical observation efficiency and scientific output, reduces instrument construction operation cost and equipment loss, applicable to the high-resolution fiber spectrometer of all kinds of cathode lamp asynchronous calibration.