28 March 2016 Enhanced optical discrimination system based on switchable retroreflective films
Author Affiliations +
Optical Engineering, 55(4), 045101 (2016). doi:10.1117/1.OE.55.4.045101
Reported herein is the design, characterization, and demonstration of a laser interrogation and response optical discrimination system based on large-area corner-cube retroreflective films. The switchable retroreflective films use light-scattering liquid crystal to modulate retroreflected intensity. The system can operate with multiple wavelengths (visible to infrared) and includes variable divergence optics for irradiance adjustments and ease of system alignment. The electronic receiver and switchable retroreflector offer low-power operation (<4  mW standby) on coin cell batteries with rapid interrogation to retroreflected signal reception response times (<15  ms). The entire switchable retroreflector film is <1  mm thick and is flexible for optimal placement and increased angular response. The system was demonstrated in high ambient lighting conditions (daylight, 18k lux) with a visible 10-mW output 635-nm source out to a distance of 400 m (naked eye detection). Nighttime demonstrations were performed using a 1.5-mW, 850-nm infrared laser diode out to a distance of 400 m using a night vision camera. This system could have tagging and conspicuity applications in commercial or military settings.
© 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)
Phillip Schultz, Jason C. Heikenfeld, "Enhanced optical discrimination system based on switchable retroreflective films," Optical Engineering 55(4), 045101 (28 March 2016). https://doi.org/10.1117/1.OE.55.4.045101



Light sources


Optical filters

Free space optics

Liquid crystals


Fiber optics for perimetry-based on video-oculography
Proceedings of SPIE (July 28 1994)
New constructions of antilaser filters
Proceedings of SPIE (March 01 1995)

Back to Top