Bistability control of phase conjugate reflectivity by erase beam in photorefractive four-wave mixing

✍ Scribed by Hajime Okada; Atsushi Okamoto; Yoshihisa Takayama; Kunihiro Sato

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 247 KB
• Volume: 83
• Category: Article
• ISSN: 8756-663X
• DOI: 10.1002/(sici)1520-6432(200006)83:6<8::aid-ecjb2>3.0.co;2-y

✦ Synopsis

When the nonlinear effect of the crystal is strong in four-wave mixing using a photorefractive crystal, the generated phase conjugate light takes multiple values. In this paper, a new method of controlling the bistable values of the phase conjugate reflectivity, that is, the ratio of the phase conjugate beam to the probe beam, via the erase beam is proposed for use in four-wave mixing using the fanning beam generated in the crystal in place of the forward pump beam. It is extremely difficult to solve analytically the problem of four-wave mixing including the fanning beam. By means of a model in which a part of the probe beam is used for fanning and acts as the forward pump beam in the interaction region, the previous method of analysis for four-wave mixing can be used. First, a steady-state analysis of the phase conjugate reflectivity is carried out. It is shown that the phase conjugate reflectivity has bistable values as function of the intensity of the erase beam. Next, by time response analysis, the intensity of the erase beam is varied and the bistable values of the phase conjugate reflectivity are controlled. Finally, the theory is compared with experiments.