Electro-optic frame photography with pulsed ruby illumination

Abstract

By combining the attributes ofelectro-optic shuttering and pulsedlaser illumination in alarge format camera system, we have developed a multi-frame image converter camera with a laser illuminator that produces sequentialphotographs offast phenomena with very high resolution. The combination ofthe large size image plane (75 mm), short exposure time per frame (minimum 12-15 ns), and monochromatic laser illumination provides clear, sharp, front-lit images of surfaces and shapes with no degradation by luminous air shocks or motion blur. The unique modular design ofthe camera and the laser allow for a variety ofconfigurations and applications. The current camera system produces eight independent pictures or four stereo pairs. A Q-switched ruby laser with multiple pulse capability provides individual illumination for each frame. This system has photographed a variety of fast phenomena including the first stereo sequential photographs of the initial formation and early time history of high velocity shaped-charge jets.

Feasibility analysis and demonstration of high-speed digital imaging using micro-arrays of vertical cavity surface-emitting lasers

“…The specific heat of copper is 0.385 J/g o K; therefore, for 100 g of copper submount the temperature increase is only 2.5 • C, which allows passive cooling. [7][8][9][10]…”

MHz class repetitively Q-switched, high-power ruby lasers for high-speed photographic applications

“…This camera allows researchers to capture multiple high-speed events using solid state technology housed in a 53 in. 3 package.…”

“…Shaw et al is an example of a custom ruby laser system, = 694 nm, that combines the capability of using four separate regions of a ruby rod for separate Q-switched laser cavities as well as to have two of these units to form a pulse train of up to eight pulses. [2][3] Francis on the other hand, used four commercially available frequency doubled Nd:YAG lasers, = 532 nm, each with a single or double pulse output waveform. 4 The use of multiple independently triggered lasers does provide enhanced timing flexibility , i.e., to obtain pulse repetition rates in excess of 1 MHz.…”