Title

Optical-Cavity-Based Multiwavelength Sensor for Spectral Discrimination and Object Position Detection

Document Type

Journal Article

Faculty

Faculty of Computing, Health and Science

School

Electron Science Research Institute (ESRI)

RAS ID

13115

Comments

Originally published as: Venkataraayan, K., Askraba, S., Alameh, K. E., & Smith, C. L. (2011). Optical-Cavity-Based Multiwavelength Sensor for Spectral Discrimination and Object Position Detection. Journal of Lightwave Technology, 29(16), 2365-2371. Original available here

Abstract

An intruder detection and discrimination sensor with improved optical design is developed using lasers of different wavelengths to demonstrate the concept of discrimination over a distance of 6 m. A distinctive feature of optics is used to provide additional transverse laser beam scanning. The sample objects used to demonstrate the concept of discrimination over a distance of 6 m are leaf, bark, black fabric, PVC, wood and camouflage material. A camouflage material is chosen to illustrate the discrimination capability of the sensor. The sensor utilizes a five-wavelength laser combination module, which sequentially emits identically-polarized laser light beams along one optical path. A cylindrical quasi-optical cavity with improved optical design generates multiple laser light beams for each laser. The intensities of the reflected light beams from the different spots are detected using a high speed area scan image sensor. Object discrimination and detection is based on analyzing the Gaussian profile of reflected light at the different wavelengths. The discrimination between selected objects is accomplished by calculating four different slopes from the objects' reflectance spectra at the wavelengths 473 nm, 532 nm, 635 nm, 670 nm and 785 nm. Furthermore, the camouflage material, which has complex patterns within a single sample, is also detected and discriminated over a 6 m range by scanning the laser beam spots along the transverse direction. --------------------------------------------------------------------------------

 

Link to publisher version (DOI)

10.1109/JLT.2011.2158571