Reconfigurable Multiple Beam Laser Doppler Vibrometer

Photonics Optics Tech proposes to develop an innovative reconfigurable multiple beam Laser Doppler Vibrometer (RMBLDV) system to meet with the real-time in-situ airframe defect inspection needs. This RMBLDV system utilizes high-speed high-efficiency Phase-only Spatial Light Modulator together with Computer Generated Hologram (CGH) to produce high density (up to 64 x 64 laser beam array), reconfigurable diffraction pattern (with various CGH) that can accommodate a variety of shape and size of the airframe under inspection. To build a compact system, the system utilizes a new low-voltage; lightweight Phase Modulator (PM) to obtain the Doppler carrier frequency and a CMOS photodetector array for direct output laser beam integration and detection. The designed system performance specifications include: high speed (video rate for vibration pattern update), compact (size of a professional video camera), mobile (optics and electronic system are integrated in a single package), eye-safe (minimum laser power needed due to the high-efficiency POSLM/CGH diffraction device). The resultant new system design is compact, highly mobile, low power, and eye-safe that will enable single shot simultaneous measurement of the structure integrity of a variety of air frames in a variety of air field environments.   BENEFITS: Unique advantages of the POT proposed RMBLDV system includes: 1) low power laser (10 x lower compared with SOA multiple beam LDV system) needed due to the use of high-efficient CGH component for single-to-multiple beam conversion. 2) High-density (up to 64 x 64 beam array), reconfigurable (laser beam distribution pattern reconfigurable to map the object under inspection) multiple beam for simultaneous single-shot inspection. 3) Compact (size of a professional video camera), highly mobile (integrated optics head and electronic subsystem in a single compact package) to enable in-situ testing at challenging air field environment. Other commercial applications include: aircraft, ship, and automobile system integrity inspection, field or on-orbit spacecraft surface/thermal tile embedded defect inspection.