Method and apparatus for determing the wavelength of an input light beam
AssigneeFizeau Electro-Optic Systems, LLC
InventorsJames J. Snyder, Stephen L. Kwiatkowski
Life of this patent
Estimating the term…
Abstract
A method and apparatus for measuring the wavelength of an input light beam whereby the input light beam is split into two light beams which are directed through two paths of different optical length. The light beams are interfered with each other in order to form a fringe pattern at an observation plane, which fringe pattern is detected and analyzed to thereby determine the wavelength of the input light beam.
Claims60
An apparatus for measuring the wavelength of an input light beam, the apparatus comprising:
- an optical device having an input port and two output ports, the optical device defining first and second optical paths which operate to direct light from the input port to the first and second output ports, respectively, and which have optical lengths which differ by a first optical length difference, wherein the two output ports are separated by a separation distance such that light exiting the optical device through the two output ports forms, at an observation plane disposed at a second distance from the two output ports, a fringe pattern whose configuration at the observation plane is a function of the wavelength of the input light beam;
- a photo detector adapted to generate one or more detection signals in response to said fringe pattern;
- and
- a processor implementing a process for analyzing said one or more detection signals to thereby determine the wavelength of the input light beam.
A method for measuring the wavelength of an input light beam, the method comprising:
- launching the input light beam into a waveguide;
- splitting the input light beam in the waveguide into two light beams;
- directing the two light beams through two paths of different optical length;
- interfering light exiting said two paths to thereby form a fringe pattern at an observation plane;
- detecting the fringe pattern;
- and
- analyzing the configuration of said detected fringe pattern to thereby determine the wavelength of the input light beam.
An apparatus for measuring the wavelength of an input light beam, the apparatus comprising:
- means for splitting the input light beam into two light beams;
- means for directing the two light beams through two paths of different optical length;
- means for causing light exiting the two paths to interfere such that a fringe pattern is formed at an observation plane;
- means for detecting the fringe pattern;
- and
- means for analyzing the configuration of said detected fringe pattern.
An apparatus for measuring the wavelength of an input light beam, the apparatus comprising:
- an optical device having an input port and two output ports, the optical device defining first and second optical paths which operate to direct light from the input port to the first and second output ports, respectively, and which have optical lengths which differ by a first optical length difference, wherein the two output ports are separated by a separation distance such that light exiting the optical device through the two output ports forms, at an observation plane disposed at a second distance from the two output ports, a fringe pattern whose configuration at the observation plane is a function of the wavelength of the input light beam;
- a photo detector adapted to generate one or more detection signals in response to said fringe pattern;
- and
- a processor implementing a process for analyzing the one or more detection signals to thereby determine the wavelength of the input light beam, said process including:
- determining the average spacing between fringes and computing therefrom the wavelength of said incident radiation;
- determining the exact order number of the light to a reference point on said photo detector;
- determining the optical delay at said reference point on said photo detector;
- and
- computing from said exact order number and said high accuracy optical delay the wavelength of said input light beam.
The apparatus of 44, wherein the photo detector responds to light of wavelengths in the range of from about 0.4 μm to about 1.1 μm.
Dependencies are inferred from the claim text.