TIME-GATED IMAGING THROUGH DENSE SCATTERERS WITH A RAMAN AMPLIFIER

A time-gated Raman amplifier has been used to detect a bar chart hidde n by a strongly scattering material. The time gating was provided by a frequency-doubled Nd:YAG pump laser having a pulse duration of 30 ps. We have amplified and detected images with resolved structures smalle r than 125 mu m through suspensions of polystyrene spheres and nondair y creamer for light extinction factors of up to e(33). The Raman ampli fier system has been shown to produce images under conditions in which the scattering medium was sufficiently dense that an image could not be detected on either a streak camera or by integration on a sensitive , low-noise camera.