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US 6,144,025 AGranted
Laser light source apparatus
AssigneeSantec Corporation
InventorsDaikou Tei, Naoyuki Mekada
Life of this patent
Estimating the term…
Abstract
The light emitted by a laser diode 1 is entered into a beam splitter 5, and its reflected light is given to an optical band pass filter 8. The light passing through the optical band pass filter 8 is received by a photo diode PD1. The light once reflected by the optical band filter 8 and passing through the beam splitter 5 is received by a photo diode PD2. The reception ratio of the photo diodes PD1, PD2 is calculated in output ratio calculator 9. By controlling the emission wavelength of the laser diode 1 so that its ratio may be constant, laser light of high precision and stable wavelength is emitted.
Claims30
A laser light source apparatus comprising:
- a laser light source which generates laser light capable of continuously varying the wavelength thereof;
- a beam splitter for receiving laser light from said laser light source, and splitting the incident laser light into transmitted light and split light;
- an optical filter for receiving said split light from said beam splitter, and transmitting light of specified wavelength and reflecting the remainder to enter again into said beam splitter;
- a first photo detector for receiving the transmitted light from said optical filter;
- a second photo detector for receiving the light passing through said beam splitter out of the split light reflected by said optical filter;
- an output ratio calculator which calculates the output ratio of reception levels delivered from said first and second photo detectors;
- and
- a wavelength controller which controls the emission wavelength of said laser light source in a manner that the output ratio by said output ratio calculator becomes a specified value.
5 more elements
A laser light source apparatus comprising:
- a laser light source which generates laser light capable of continuously varying the wavelength thereof;
- a beam splitter for receiving laser light from said laser light source, and splitting the incident laser light into transmitted light and split light;
- an optical filter composed of an interference optical filter laminating low refractive index films and high refractive index films having optical thicknesses of .lambda./4 for transmission wavelength .lambda. on a substrate alternately in multiple layers, and continuously changing the optical thicknesses in a specified direction of said substrate so that the transmission wavelength .lambda. changes continuously in a specific direction of the substrate, for receiving said split light from said beam splitter, and transmitting light of specified wavelength and reflecting the remainder to enter again into said beam splitter;
- a first photo detector for receiving the light transmitted through said optical filter;
- a second photo detector for receiving the light passing through said beam splitter out of the split light reflected by said optical filter;
- an output ratio calculator which calculates the output ratio of reception levels delivered from said first and second photo detectors;
- a wavelength controller which controls the emission wavelength of said laser light source in a manner that the output ratio by said output ratio calculator becomes a specified value;
- and
- a slide adjusting mechanism for changing the incident position of said split and reflected light into said optical filter continuously in said specified direction.
6 more elements
A laser light source apparatus comprising:
- a laser light source which generates laser light capable of continuously varying the wavelength thereof;
- a beam splitter for receiving laser light from said laser light source, and splitting the incident laser light into transmitted light and split light;
- an optical filter for receiving said split light from said beam splitter, and transmitting light of specified wavelength and reflecting the remainder to enter again into said beam splitter;
- a first photo detector for receiving the transmitted light from said optical filter;
- a second photo detector for receiving the light passing through said beam splitter out of the split light reflected by said optical filter;
- and
- a processing unit which controls said laser light source based on the signals of said first and second photo detectors, for performing the following operations:
- detecting the ratio of the output signals of said first and second photo detectors,
- detecting the difference between said detected ratio and a predetermined reference value, and
- outputting the control signal for controlling the emission wavelength of said laser light source in a manner that said difference becomes zero.
7 more elements
A laser light source apparatus comprising:
- a laser light source which generates laser light capable of continuously varying the wavelength thereof;
- a beam splitter for receiving laser light from said laser light source, and splitting the incident laser light into transmitted light and split light;
- an optical filter composed as an interference optical filter laminating low refractive index films and high refractive index films having optical thicknesses of .lambda./4 for transmission wavelength .lambda. on a substrate alternately in multiple layers, and continuously changing the optical thicknesses so that the transmission wavelength .lambda. change continuously in a specific direction of the substrate, for receiving light of a laser light source capable of changing wavelength of light continuously, for receiving said split light from said beam splitter, and transmitting light of specified wavelength and reflecting the remainder to enter again into said beam splitter;
- a first photo detector for receiving the transmitted light from said optical filter;
- a second photo detector for receiving the light passing through said beam splitter out of the split light reflected by said optical filter;
- and
- a processing unit which controls said laser light source based on the signals of said first and second photo detectors, for performing the following operations:
- detecting the ratio of the output signals of said first and second photo detectors,
- detecting the difference between said detected ratio and a predetermined reference value, and
- outputting the control signal for controlling the emission wavelength of said laser light source in a manner that said difference becomes zero.
7 more elements
Dependencies are inferred from the claim text.