Holographic module HOLO
Novel contactless and versatile device HOLO is attachable to any pulsed laser source for investigation of nonlinear optical and photoelectric phenomena in semiconductors. It exploits four-wave mixing configuration of the well-known “pump-probe” technique.
Features
- Grating recording wavelength 266, 355, 532 or 1064 nm
- Probe beam wavelength 532 or 1064 nm
- Excitation energy flux density 0.1–10 mJ/cm2
- Probe beam delay range 1500 ps
- Laser pulse duration range 5–50 ps
- Dynamic grating period range 2–20 µm
- Minimal probe beam diameter 100 µm
Range of Material Parameters
- Diffusion coefficient D = 0.1–50 cm2/s
- Carrier lifetime τR = 0.1–10 ns
- Surface recombination velocity S = 104–106 cm/s
HOLO-module is a novel laser spectroscopy device for contactless investigation and optical diagnostics of carrier generation, transport and relaxation processes in bulk semiconductor crystals, epilayers and heterostructures. It exploits four-wave mixing configuration of the well-known “pump-probe” technique. HOLO operation is based on recording of refractive index spatial modulation by interference field of two picosecond laser pulses, and subsequent probing of modulation decay by a delayed probe beam. HOLO is applicable for measurements of carrier generation rate, photoinduced carrier concentration, bipolar diffusion coefficient, carrier recombination time and surface recombination rate. The device also allows planar monitoring (mapping) of diffraction efficiency and homogeneity of defect distribution in a wafer.