High Sensitivity Rugged Array Detectors for Field Deployed Instruments: Low-Light Level Camera for Laser-Induced Breakdown Spectroscopy (LIBS) and Ram

Laser-induced breakdown spectroscopy (LIBS) and Raman spectroscopy are developing rapidly for chemical and biochemical sensing applications. There is an urgent need for high-sensitivity detectors so as to minimize sample quantity and maximize detection range from the source. In most field-deployable spectrometers, a photo-detector array is used for analyzing the spectral contents. The sensitivities of the CCD or CMOS arrays are typically not high enough, and an expensive and short-lived ICCD has to be used. We proposed in Phase I the world’s first nano-tech semiconductor image intensifier and low-light-level camera design. During Phase I, we also built the world’s first femto-Amp femto-Watt electro-optical measurement system, fabricated the world’s highest sensitivity semiconductor photo-detectors, and precisely characterized them to have achieved > 100 x higher sensitivity than avalanche photodiodes. Our Phase I experimental results well exceeded our original expectations. Phase II will see the full specification development of the proposed image intensifier, low-light-level camera and high-sensitivity LIBS systems. The prototype LIBS spectrometer will cover 200 – 1,000 nm range with 0.1 nm resolution. It will have its detection limit as low as 1/1,000 of the minimum detectable amount of a similar system with CCD. We will continue into production in Phase III.