Light source unit and light irradiation unit
AssigneeNikon Corporation
InventorsAkira Tokuhisa, Hiroshi Kitano, Hitoshi Kawai
Life of this patent
Estimating the term…
Abstract
In nonlinear optical crystal 183D, each step of wavelength conversion can be performed using another fundamental wave that is output from light output unit 1612, without using the fundamental wave whose output level has been attenuated after going through wavelength conversion for several steps (wavelength conversion in nonlinear optical crystals 183A to 183C). Therefore, the wavelength conversion efficiency improves and the peak power of optical amplifiers 1611 and 1612 can be suppressed, which allows the wavelength of lights that are output from optical amplifiers 1611 and 1612 to be further narrowed.
Claims20
A light source unit that generates light having a predetermined wavelength, said unit comprising:
- a plurality of light output units that output lights having wavelengths different from said predetermined wavelength;
- and
- a wavelength converter that generates light having said predetermined wavelength by wavelength conversion in a plurality of steps which include wavelength conversion using two lights as incident lights whose fundamental waves are severally output from different light output units of said plurality of light output units, wherein
- at least one unit of said plurality of light output units is a first unit that outputs light of a first wavelength, and at least one unit of said plurality of light output units is a second unit that outputs light of a second wavelength different from light of said first wavelength,
- wavelength conversion of said wavelength converter includes wavelength conversion in which the m-fold wave (m:
- natural number) of said light having the first wavelength output from said first unit and the n-fold wave (n:
- natural number) of said light having the second wavelength output from said second unit enter said converter to generate a sum-frequency of said m-fold wave and said n-fold wave,
- one unit of said first unit and said second unit is in plurals, and
- said wavelength conversion of said wavelength converter further includes wavelength conversion that generates a sum-frequency of said generated sum-frequency and light output from the other said one unit, which is not used for generating said sum-frequency.
A light source unit that generates light having a predetermined wavelength, said unit comprising:
- a plurality of light output units that output lights having wavelengths different from said predetermined wavelength;
- and
- a wavelength converter that generates light having said predetermined wavelength by wavelength conversion in a plurality of steps which include wavelength conversion using two lights as incident lights whose fundamental waves are severally output from different light output units of said plurality of light output units, wherein
- at least one unit of said plurality of light output units is a first unit that outputs light of a first wavelength, and at least one unit of said plurality of light output units is a second unit that outputs light of a second wavelength different from light of said first wavelength, and
- said first unit is an ytterbium doped optical fiber amplifier, and said second unit is at least one of an erbium doped optical fiber amplifier, a thulium doped optical fiber amplifier and a holmium doped optical fiber amplifier.
Dependencies are inferred from the claim text.