Laser source apparatus and laser microscope

Patent metadata

Field	Value
Publication number	US-9356413-B2
Application number	US-201213625228-A
Country	US
Kind code	B2
Filing date	Sep 24, 2012
Priority date	Sep 30, 2011
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

Provided is a laser source apparatus including a single laser source that emits an ultrashort-pulse laser beam; a wavelength conversion mechanism that generates a plurality of pulsed laser beams having different wavelengths by converting at least a part of wavelength of the ultrashort-pulse laser beam; a dispersion adjusting section that adjusts the amount of frequency dispersion for each of the pulsed laser beams; and an introducing optics that emits the plurality of pulsed laser beams whose frequency dispersion amounts are adjusted by the dispersion adjusting section. The dispersion adjusting section adjusts the amount of frequency dispersion for each of the pulsed laser beams so that each of the pulsed laser beams introduced to the irradiation optics of the optical apparatus from the introducing optics to excite a specimen is close to a substantially Fourier-transform-limited pulse.

First claim

The invention claimed is:

1. A laser source apparatus for an optical apparatus that is provided with an irradiation optics which irradiates a specimen, the laser source apparatus comprising:
a single laser source that emits an ultrashort-pulse laser beam;
a splitting device that splits the ultrashort-pulse laser beam emitted from the laser source into two first pulsed laser beams;
a wavelength conversion device that converts a wavelength of one of the two first pulsed laser beams obtained by the splitting by the splitting device, to generate at least one second pulsed laser beam having a wavelength different from the wavelength of said one first pulsed laser beam;
a first dispersion-compensating optics that is disposed in a light path of the other of the two first pulsed laser beams obtained by the splitting by the splitting device and that applies negative frequency dispersion to said other first pulsed laser beam such that said other first pulsed laser beam is close to a substantially Fourier-transform-limited pulse at the specimen, wherein a wavelength of said other first pulsed laser beam is not converted;
a second dispersion-compensating optics that is disposed in a light path of the at least one second pulsed laser beam generated by the wavelength conversion device and that applies negative frequency dispersion to the second pulsed laser beam such that the second pulsed laser beam is close to a substantially Fourier-transform-limited pulse at the specimen; and
an introducing optics that comprises a beam combining device which combines said other first pulsed laser beam to which negative frequency dispersion is applied by the first dispersion-compensating optics and the at least one second pulsed laser beam to which negative frequency dispersion is applied by the second dispersion-compensating optics, and that emits to the irradiation optics of the optical apparatus a third pulsed laser beam obtained by the combining using the beam combining device;
wherein the wavelength conversion device comprises:
a second harmonic generation device that converts said one first pulsed laser beam to generate a laser beam whose wavelength is half the wavelength of said one first pulsed laser beam and that outputs the laser beam; and
an optical parametric oscillator that generates the at least one second pulsed laser beam by converting the wavelength of the laser beam output from the second harmonic generation device.

2. The laser source apparatus according to claim 1 , wherein the first dispersion-compensating optics and the second dispersion-compensating optics respectively comprise one of a prism pair, a grating pair, and chirped mirrors.

3. The laser source apparatus according to claim 1 , further comprising a power modulator that modulates a power of each of said other first pulsed laser beam and the at least one second pulsed laser beam.

4. The laser source apparatus according to claim 3 , wherein the power modulator comprises one of an acousto-optic modulator and an electro-optic modulator.

5. The laser source apparatus according to claim 3 , wherein the power modulator turns the power of each of said other first pulsed laser beam and the at least one second pulsed laser beam on and off.

6. The laser source apparatus according to claim 3 , further comprising a beam-shaping optics that adjusts a wavefront shape of each of said other first pulsed laser beam and the at least one second pulsed laser beam.

7. The laser source apparatus according to claim 3 , wherein the power modulator comprises a plurality of power modulators which are respectively disposed in the light paths of said other first pulsed laser beam and the at least one second pulsed laser beam.

8. The laser source apparatus according to claim 1 , further comprising a beam-shaping optics that adjusts a wavefront shape of each of said other first pulsed laser beam and the at least one second pulsed laser beam.

9. The laser source apparatus according to claim 8 , wherein the beam-shaping optics comprises a plurality of beam-shaping optics which are respectively disposed in the light paths of said other first pulsed laser beam and the at least one second pulsed laser beam.

10. The laser source apparatus according to claim 1 , further comprising a positive dispersion device, disposed between the splitting device and the wavelength conversion device, that applies positive frequency dispersion to said one first pulsed laser beam obtained by the splitting using the splitting device such that said one first pulsed laser beam becomes a substantially Fourier-transform-limited pulse at a position where said one first pulsed laser beam enters the wavelength conversion device.

11. The laser source apparatus according to claim 1 , wherein the splitting device is a half-mirror.

12. The laser source apparatus according to claim 1 , wherein the beam combining device includes a dichroic mirror.

13. A laser source apparatus for an optical apparatus that is provided with an irradiation optics which irradiates a specimen, the laser source apparatus comprising:
a single laser source that emits an ultrashort-pulse laser beam;
a splitting device that splits the ultrashort-pulse laser beam emitted from the laser source into two first pulsed laser beams;
a wavelength conversion device that converts a wavelength of one of the two first pulsed laser beams obtained by the splitting by the splitting device, to generate at least one second pulsed laser beam having a wavelength different from the wavelength of said one first pulsed laser beam;
a first dispersion-compensating optics that is disposed in a light path of the other of the two first pulsed laser beams obtained by the splitting by the splitting device and that applies negative frequency dispersion to said other first pulsed laser beam such that said other first pulsed laser beam is close to a substantially Fourier-transform-limited pulse at the specimen, wherein a wavelength of said other first pulsed laser beam is not converted;
a second dispersion-compensating optics that is disposed in a light path of the at least one second pulsed laser beam generated by the wavelength conversion device and that applies negative frequency dispersion to the second pulsed laser beam such that the second pulsed laser beam is close to a substantially Fourier-transform-limited pulse at the specimen;
an introducing optics that comprises a beam combining device which combines said other first pulsed laser beam to which negative frequency dispersion is applied by the first dispersion-compensating optics and the at least one second pulsed laser beam to which negative frequency dispersion is applied by the second dispersion-compensating optics, and that emits to the irradiation optics of the optical apparatus a third pulsed laser beam obtained by the combining using the beam combining device;
wherein:
the wavelength conversion device generates a plurality of the second pulsed laser beams, the plurality of second pulsed laser beams having different wavelengths;
the wavelength conversion device comprises an optical parametric oscillator that generates a signal laser beam and an idler laser beam as the plurality of the second pulsed laser beams having different wavelengths;
the laser source apparatus further comprises a second splitting device that splits the plurality of second pulsed laser beams into a plurality of light paths according to wavelength, the second splitting device splitting the signal laser beam and the idler laser beam into different light paths among the plurality of light paths;
the second dispersion-compensating optics comprises a plurality of second dispersion-compensat

Assignees

• Olympus Corp

Inventors

• Kubo Hirokazu

Classifications

• H01S3/0057 Primary

  Temporal shaping, e.g. pulse compression, frequency chirping (soliton generation and propagation G02F1/3513, H01S3/063 and H01S3/108) · CPC title

• G02F1/3532

  Arrangements of plural nonlinear devices for generating multi-colour light beams, e.g. arrangements of SHG, SFG, OPO devices for generating RGB light beams · CPC title

• G02F1/39

  for parametric generation or amplification of light, infrared or ultraviolet waves · CPC title

• G02B21/0032

  Optical details of illumination, e.g. light-sources, pinholes, beam splitters, slits, fibers (G02B21/0036 - G02B21/008; means for illumination of specimens in general G02B21/06) · CPC title

• H01S3/0092

  Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity (nonlinear frequency conversion per se G02F1/35) · CPC title