Optical Power Limiters

Brimrose proposes to produce an improved material for optical power l miting at near infrared wavelengths to protect sensors against jamming and to build a prototype device. The proposed material, vanadium doped cadmium telluride, is relatively new and will be used to fabricate an electro-optic power limiter (EOPL). This approach of using a doped II-VI semiconductor for power limiting was first demonstrated by Dr. Steier's research group at the Center or Photonics Technology at the University of Southern California ref 6 of proposal]. In close collaboration with the U.S.C. group, Brimrose has developed various transition metal doped II-VI compounds for photorefractive optical image processing. Recently, we have developed a concept of tailoring these materials for optical limiting applications. In this proposal, we will focus on two critical issues regarding EOPL operation: response time and intensity threshold. By controlling the material processing parameters, material with improved speed and sensitivity will be produced. It has already been established that the damage threshold of CdTe:V is quite superior to that of its organic and polymeric competitor materials. Furthermore, a limiter fabricated from CdTe:V will: (1) be compact in size and low in weight; (2) be simple in operation without requiring the extensive or complex external optical systems that are typically required in conventional optical limiters; and (3) exhibit low threshold with a response time in sub-microseconds. Most importantly, it will simultaneously block a high intensity jamming beam of laser radiation while still transmitting the desired low intensity image.