Tunable high speed laser illuminator and recording system

A new instrument for high-speed flow visualization will be developed and demonstrated. The system will be based on a high repitition rate pulsed Ti:Sapphire laser and high imaging rate camera. Laser technology, to be developed here, allows the laser to be pulsed at rates of 100-300 kHz for a duration of up to 1 msec. The Ti:Sapphire laser is tunable from 790-900 nm and with the addition of a non-limear crystal, the wavelength region will be extended to include 375-450 nm. For added flexibility we also propose to investigate a laser resonator which could alternate colors between two adjacent micropulses. Existing photography equipment allows 80 frames recording at rates of up to 1 MHz. Alternatively, current solid state cameras can be used for imaging and storage rates of up to 12 KHz. We propose to use the proposed system for Schlieren and shadowgraph imaging. However, we also propose to investigate the possibility of using Rayleigh scattering for planar density and qualitative velocity imaging through a Rayleigh filter.