公开(公告)号：JPH086082A

公开(公告)日：1996-01-12

申请号：JP13704694

申请日：1994-06-20

Applicant: IBM

Inventor： YAMATO SOICHI ,  TAIRA YOICHI

IPC: G02F1/35 ,  G02F1/355 ,  G02F1/37 ,  H01S3/109

Abstract: PURPOSE: To enable a resonator to be synchronized with a small easy structure without lowering optical output of a changed wavelength. CONSTITUTION: A laser beam emitted from a laser beam machine 12 is made incident on a resonator 16, whose resonance frequency is modulated in the electrical field imparted to the a BBO crystal 14 inside the resonator 16. In the BBO crystal 14, a modulation electrode 32 is arranged, as is a feedback electrode 34, so that the laser beam modulated in the BBO crystal 14 is detected by a photodetector 18. With a signal proportional to the error of the resonance frequency obtained from the photodetector 18, an electrical field is imparted to the BBO crystal 14 through the electrode 32, thereby changing the resonator length, controlling by feeding back negatively against the resonance frequency of the resonator 16 that is determined by the BBO crystal 14 through the imparting of the electrical field, and making synchronization by maintaining the error nearly on a zero level.

公开(公告)号：JPH0675257A

公开(公告)日：1994-03-18

申请号：JP20349792

申请日：1992-07-30

Applicant: IBM

Inventor： YAMATO SOICHI ,  KUMADA KIYOSHI ,  KANO SATORU

IPC: G02F1/35 ,  G02F1/017 ,  G02F1/355 ,  G02F1/37 ,  G02F1/377

Abstract: PURPOSE: To obtain a nonlinear optical device having sufficiently large nonlinearity by using a specified multiple quantum well structure in a material layer on a substrate. CONSTITUTION: The material layer formed on a substrate has a multiple quantum well structure in which insulating layers and semiconductor layers are alternately deposited and the potential for an electron in the semiconductor layer is made asymmetric in regard to the perpendicular direction to the substrate. The difference between the min. energy level in the conductive band and the max. energy level in the valence band of the semiconductor layer is controlled to about >=3eV. For example, in the figure showing a unit of the multiple quantum well structure using Nail as an insulating layer and ZnSe as a semiconductor layer, the upper solid line represents the potential for an electron in the conductive band and the lower solid line shows the corresponding potential in the valence band. The semiconductor layer has an asymmetric structure of combined quantum welts in which two ZnSe layers interpose one NaCl layer. The dot lines represent three states of an electron trapped in the well, and optical nonlinearity is produced by the transition of the electron.