公开(公告)号：JPH01274487A

公开(公告)日：1989-11-02

申请号：JP10464488

申请日：1988-04-27

Applicant: HAMAMATSU PHOTONICS KK

Inventor： MATSUMOTO OSAMU

IPC: H01S3/23 ,  G02F1/37 ,  H01S3/07 ,  H01S3/109

Abstract: PURPOSE:To improve conversion efficiency to a fourth higher harmonic by a method wherein a second higher harmonic reciprocated in a first laser resonator and converted by a first nonlinear type optical crystal is transmitted through a second mirror, reciprocated in a second laser resonator composed of a third mirror and a fourth mirror, converted into the fourth higher harmonic by a second nonlinear type optical crystal, transmitted through the fourth mirror and extracted as laser beams. CONSTITUTION:When the laser beams of a fundamental wave emitted from an Nd-YAG rod 5 are transmitted through a third mirror 3 and projected to a crystal 6, the laser beams of a second higher harmonic is output. The fundamental wave is reflected by a second mirror 2 and reflected laser beams are also reflected by a first mirror 1, thus oscillating the inside of a laser oscillator 9. When the second higher harmonic output from the first nonlinear type optical crystal 6 is transmitted through the second mirror 2 and projected to a crystal 7 in a second resonator 10, the laser beams of a fourth higher harmonic are output. The second higher harmonic is reflected by a fourth mirror 4, and is oscillated between the fourth mirror 4 and the third mirror 3. The fourth higher harmonic output from the second nonlinear type optical crystal 7 is transmitted through the fourth mirror 4, and output as the laser beams of the aimed fourth higher harmonic.

公开(公告)号：JPH01121824A

公开(公告)日：1989-05-15

申请号：JP28016287

申请日：1987-11-05

Applicant: HAMAMATSU PHOTONICS KK

Inventor： MATSUMOTO OSAMU ,  KOBAYASHI YUJI ,  OBAYASHI YASUSHI ,  SUZUKI HIDEO ,  SUZUKI TAKASHI ,  OSUMI YASUTSUGU

IPC: G02F1/37 ,  G02F1/35

Abstract: PURPOSE:To release light of a desired pattern by disposing and working an optical material at a prescribed angle with the laser light from a semiconductor laser. CONSTITUTION:This element is provided with the semiconductor laser 1, a collimating element 2 which collimates the laser light from the semiconductor laser 1 to the collimated beams of light, and the optical material 5 which releases the prescribed light by incidence of the collimated beams of light. The incident face 6 of the optical material, i.e., a nonlinear optical crystal 5 is cut at the prescribed angle delta. The nonlinear optical crystal 5 is so disposed that the collimated beams of light from the collimating element 2 enters the incident face 6 at the prescribed angle theta. The collimated beams of light having the elliptical pattern enters the incident face 6 of the nonlinear optical crystal 5 at the incident angle theta and, therefore, the collimated beams of light can be corrected to the circular pattern and can be advanced within the nonlinear optical crystal 5. The optical element which can release the light of the desired pattern is thereby obtd.

公开(公告)号：JPS63258087A

公开(公告)日：1988-10-25

申请号：JP9290787

申请日：1987-04-15

Applicant: HAMAMATSU PHOTONICS KK

Inventor： SUZUKI HIDEO ,  OSUMI YASUTSUGU ,  MORITA NOBUHIRO ,  MATSUMOTO OSAMU ,  KOBAYASHI YUJI ,  OBAYASHI YASUSHI

IPC: H01S3/10 ,  H01S3/109

Abstract: PURPOSE:To obtain a device which can be easily and accurately made and altered in wavelength setting by a method wherein incident angles of both excited light of a light parametric oscillator and oscillating light of a harmonics generator are rendered to be coincident with set angles stored in memory respectively by controlling a driving means. CONSTITUTION:A parametric oscillator 21, a harmonics generator 22, a driving means 46 changing incident angle of excited light 23 incident on a nonlinear optical crystal 28 of the oscillator 21, a driving means 47 changing incident angle of oscillating light 31 incident on a non-linear optical crystal 34 of the harmonics generator 22, an angle detection circuit 41 detecting incident angle of the excited light 23, an angle detection circuit 42 detecting incident angle of oscillating light 31, a memory 43 storing incident angles of the excited light 23 and the oscillating light 31 corresponding to plural wavelengths as setting values, a wavelength selection circuit 44, and a computing control means 45 controlling the drive means 46 and 47 on the computed output obtained in such way wherein an incident angle corresponding to a selecting signal acquired from the circuit 44, which is compared with a detected incident angle and computed so as to output the computed result, are provided.

公开(公告)号：JPS63165826A

公开(公告)日：1988-07-09

申请号：JP31090786

申请日：1986-12-27

Applicant: HAMAMATSU PHOTONICS KK

Inventor： MATSUMOTO OSAMU ,  KOBAYASHI YUJI ,  OBAYASHI YASUSHI ,  SUZUKI HIDEO ,  MORITA NOBUHIRO ,  OSUMI YASUTSUGU

IPC: H01S3/10 ,  G02F1/37 ,  G02F1/39 ,  H01S3/108 ,  H01S3/109

Abstract: PURPOSE:To prevent an optical axis from being sheared by providing the mirror to correct the shear of the optical axis generated at the time of turning a non- linear optical crystal face and moving the mirror. CONSTITUTION:A signal for obtaining a projecting laser beams with an objective wavelength lambda is inputted from an input terminal 25 to a CPU 23. The CPU 23 rotates the non-linear optical crystal 6 by a prescribed angle theta through a driving circuit 21 and a crystal driving part 12. Since the wavelength of the projecting laser beam is changed, the optical axis 13 is moved in parallel by a prescribed distance (d). Simultaneously, a signal corresponding to the parallel moving distance (d) is set from the CPU 23 to a driving circuit 22 in a mirror driving device 18 to rotate a mirror driving part 19. Since the mirror 14 is moved by the rotation and the moving distance (d) is corrected, an optical axis 26 after diffraction based upon the mirror 14 is always allowed to coincide. An optical axis 27 parallel with the optical axis 10 of the incident laser beam is obtained by reflecting the optical axis 26 by a mirror 20.

公开(公告)号：JPS63133686A

公开(公告)日：1988-06-06

申请号：JP28126986

申请日：1986-11-26

Applicant: HAMAMATSU PHOTONICS KK

Inventor： MATSUMOTO OSAMU ,  KOBAYASHI YUJI ,  OBAYASHI YASUSHI ,  SUZUKI HIDEO ,  MORITA NOBUHIRO ,  OSUMI YASUTSUGU

IPC: H01S3/10 ,  H01S3/108

Abstract: PURPOSE:To prevent damage or breakdown of nonlinear optical crystal due to excessive power density of incident laser beam to nonlinear optical crystal by providing a particular half-mirror, a power density detector, a comparator and a light shielding mechanism. CONSTITUTION:A variable-wavelength laser device 11 which changes wavelength of laser beam 13a emitted therefrom by changing a relative incident angle for crystal surface of laser beam 13 incident to nonlinear optical crystal 16 is provided with a half-mirror 21 for branching the laser beam 13 incident to the nonlinear optical crystal 15, a power density detector 31 for detecting power density of branched laser beam 13, a comparator 33 for comparing a detected value of power density detector 31 with the present value and a light shielding mechanism 20 for shielding the laser beam 13 incident to the nonlinear optical crystal 16 based on an output of the comparator 33. The light shielding mechanism 20 is structured, for example, a shutter 26 adjacent to the optical axis of laser beam 13, a solenoid 30 to drive the shutter and a solenoid drive circuit 23 to drive the solenoid 30 based on an output of comparator 33.