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Transient-type stimulated emission in the terahertz frequency range has been achieved from silicon crystals doped by phosphorus and bismuth donors under optical excitation by a few picosecond-long pulses generated by the infrared free electron lasers, FELIX and CLIO. The lasing emission occurs due to a population inversion based mechanism for different interpulse intervals (40 ns, 20 ns, 16 ns, 1...
A single-color pump-probe system has been commissioned at the Novosibirsk free electron laser facility. Monochromatic laser radiation with a bandwidth of about 1% can be tuned within the spectral ranges of 90–240 and 30–90 μΜ. The laser emits radiation as a continuous stream of 100-ps pulses with a repetition rate of 5.6 MHz. The average radiation power can reach 100 W. The temperature of samples...
A single-color pump-probe system has been commissioned at the Novosibirsk free electron laser. The laser emits a tunable monochromatic terahertz radiation. To prove the proper system operation, we investigated the time-resolved absorption of a sample of n-type germanium doped with antimony, which was previously investigated at the FELBE facility, in the temperature range from 5 to 40 K. The measured...
A broad-band fast germanium detector based on unipolar and bipolar photoconductivity has been demonstrated. Typical response times are about 200 ps. Such short times are realized by using heavily doped and highly compensated germanium crystals.
A possible way to create silicon terahertz laser under electric field excitation is presented. Electrical pulses with both period and duration in nanosecond range should be applied to moderately doped stressed bulk silicon. The purpose of short pulse excitation is impurity breakdown followed by capture and population of upper lasing state. The mechanisms responsible for population inversion and losses...
It has been demonstrated that external uniaxial stress applied to silicon crystals doped by bismuth and antimony influences on the emission spectrum of intracenter lasers under CO2 laser pumping. For small stress the spin-orbit coupling of lower laser working states can be tuned. The details of frequency change depend on crystallographic orientation and donor element.
Terahertz stimulated emission (4-6 THz) from optically excited group-V donors (phosphor P, antimony Sb, arsenic As, bismuth Bi) in axially compressed silicon crystal has been studied. As shown CW laser operation of P, Sb, As donors become reachable due to the laser threshold decrease induced by the stress.
Liquid helium temperature experimental study of terahertz (4-6 THz) lasing of optically excited group-V donors in axially compressed silicon crystal are presented and discussed.
New principals to generate stimulated emission in terahertz frequency range from silicon doped by shallow donor centers have been demonstrated. Lasing in the frequency bands of 1.2 – 1.8 THz; 2.5 – 3.4 THz, 5.0 – 5.2 THz and 6.1 – 6.4 THz, has been achieved from silicon crystals doped by phosphorus to ∼1015 cm−3, under optical pumping by radiation of mid-infrared free electron laser at cryogenic temperatures...
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