Accession Number : ADA483027


Title :   Speckle Free, Low Coherency, High Brightness, and High Pulse Speed Infrared Collimated Light Sources for Mid-IR Target Designator and Hyperspectral Imaging


Descriptive Note : Final rept. 31 Jul 2006-30 Oct 2007


Corporate Author : DENSELIGHT SEMICONDUCTORS PTE LTD (SINGAPORE)


Personal Author(s) : Lam, Yee-Loy


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a483027.pdf


Report Date : 31 Oct 2007


Pagination or Media Count : 89


Abstract : The indium phosphide-based SLED is an ideal light source for eye-safe target designation and imaging at 1550 nm spectral region. Its wide spectral width ensures low coherency, which is critical for speckle free imaging. A high brightness and well-collimated output beam allow for projection of the illumination across long distances. In this project, a high brightness SLED chip that exceeds 200 mW in peak optical power output and 20 nm of spectral bandwidth at 1550 nm wavelength has been designed, developed and demonstrated. This optical power level is the highest value ever achieved, exhibiting more than 2 times improvement over baseline SLED chips operating in the same wavelength range. The SLED chip is packaged into a compact 7-pin TO-8 platform with built-in collimating aspherical lens, and the resultant transmitter optical sub-assembly (TOSA) achieved a very low beam divergence of 1 mrad. Additionally, an optical pulse stream of IOns pulse width, 0.1% duty ratio and rise and fall times of 1 ns has been demonstrated, allowing for high speed pulsed illumination applications.


Descriptors :   *LASER GUIDANCE , *ILLUMINANTS , *EYE SAFETY , SINGAPORE , DESIGN CRITERIA , CHIPS(ELECTRONICS)


Subject Categories : Electrooptical and Optoelectronic Devices
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE