Specialists of the RAS Lebedev Institute of Physics (FIAN) have designed laser diodes of a new generation operating in the spectral range of 1.060 nm. According to the Scientific Information Agency "FIAN-Inform", the permanent output of these high-efficiency diodes is up to 10 W.

In fact, we are dealing with solid-state lasers supplied with a semiconductor, or a crystal, developed on the basis of multilayer nanosize heterostructures* acting as a working medium. They were designed at the Ioffe Leningrad Institute of Physics and Technology** and used in practice in the AlGaAs-GaAs and GalnAsP-GaAs systems twenty years ago. Nevertheless, these devices, especially those generating 805-808 nm and 915-980 nm waves, are still in high demand since they are being widely used in electronic and nuclear engineering, and in high-tech medicine.

Diodes of modern lasers have small semiconductor crystals (0.1x0.5x3 mm). To pump their active area, safe low-voltage power supply sources with the operating voltage of about 2 Vare used. They are compact, portable and economical. It is not by chance that these very laser diodes, according to the Laser Focus journal (USA), make up over 60 percent of lasers produced worldwide.

The dynamic development of electronic engineering and other scientific and technical fields of knowledge calls for a constant upgrading of laser diodes, namely multiplication of their optical power, brightness, efficiency and service life. Almost all developed countries are involved with that. The USA, Germany, Britain, and France are among the world leaders. Good results in this field were also achieved by the RAS Prokhorov Institute of General Physics and FIAN (Moscow).

As reported by the Scientific Information Agency, in recent years scientists managed to increase the resource output power of lasers up to 8-10 W with the service life exceeding 5,000 hours, which is enough for solving many practical tasks. But their potential is not exhaust-

"Heterostructure, a layer structure formed as a result of close contacts of two and more heterogeneous (other, different) semiconductors, differing in the width of forbidden gaps, lattices and other parameters.--Ed.

** See: R. Suris, E. Tropp, "On Fame's Eternal Beadroll", Science in Russia, No. 2, 2010.--Ed.

ed. Specialists are working to improve the operating efficiency of laser chips up to 65 percent and more, and to develop efficient technologies of heat removal from the crystal's active zone. When all these tasks are solved, the resource power of single emission sources will be increased up to 15-20 W.

FIAN-designed laser diodes operating in the spectral range of 1.060 nm demonstrate, according to Viktor Bezotosky, Cand. Sc. (Phys. & Math.), "...high efficiency, reproducibility of watt-ampere characteristics and potentially high reliability". During 100-hour tests of eleven lasers at the output power of 8 W, the generation intensity of all sources was stable. Moreover, when the upgraded metal-coating technology was applied in heat-removing elements, "... separate samples showed a record--high efficiency for this spectral range in the continuous operating regime: the output power topped 10 W at 10 A pump current," Bezotosky said.

Experts believe: new diode lasers will have a significant effect on the production of optic date storage and transmission systems, navigation equipment, machine building (welding as well as car body, railcar and ship hull cutting, materials hardening, surface cleaning and modification), nuclear power engineering (isotope separation), controlled thermonuclear fusion, microbiology and medicine. Finally, upgraded diodes could be very useful in basic research: they could be used as emission simulators for powerful solid-state lasers operating in the spectral range of 1.047-1.064 nm or as low-cost replacement devices.

FIAN is working to improve the reliability of new laser diodes by means of high heat-transfer technologies (up to 2,000 W/mK) on the basis of artificial diamonds grown by the "plasma-CVD" method (chemical vapor deposition).

After materials provided by the Agency of Scientific Information "FIAN-Inform", 2011