Pulse proof laser diodes from Osram Opto Semiconductors:

Laser diodes advancing into industryLaser diodes advancing into industry

Source: OSRAM

MUNICH - Osram Opto Semiconductors has increased the pulse proof characteristics of its laser diodes by more than one order of magnitude. Thanks to a new material with an SQW structure (Single Quantum Well structure) and improved electro-optical properties, the laser diodes can cope much better with thermo-mechanical stress. They have a laser threshold that is up to 25% lower and efficiency that is around 15% higher. Thermo-mechanical stress arise as a result of the alternating load in the operating mode of a welding laser in which the operating current exhibits a complicated pulse sequence with respect to time. The laser diode is continually switched on and off at a frequency in the hertz range by means of appropriate current modulation. The improved pulse proof characteristics increase the reliability and the service life of the laser diodes and bring the broad application of diode-pumped solid-state lasers (DPSSLs) in industry another step closer. In the long term, DPSSLs will replace lamp-pumped systems.

In view of the large number of individual laser diodes connected in series in a welding laser, some manufacturers are also increasing the fault tolerance and therefore the life of the laser systems by building redundancy into the design of these systems. Up to now, the failure of one laser diode led to the failure of the entire laser system. Redundant design ensures that they remain in operation even if a laser diode fails. Service life requirements to be met by future welding lasers operating round the clock in a three-shift pattern will be typically 15 to 25 million cycles. Depending on the cycle time, this equates to more than 10,000 to 15,000 hours of operation, possibly more. Laser diodes therefore have to meet reliability requirements in the range of 200 to 300 ppm for an operating period of 1 million cycles. Extensive testing under actual operating conditions indicates that the statistical life expectancy will be achieved.

Background
The introduction of diode-pumped solid-state lasers (DPSSLs) helped a new laser technology to make the breakthrough in 1999. Since then, laser diodes have been increasingly used as the pump source for solid-state lasers instead of the usual discharge lamps. They are three times as efficient as discharge lamps and consume correspondingly less power. Laser diodes can pump solid state lasers with greater homogeneity than discharge lamps and therefore achieve a better beam quality. DPSSLs give laser systems a new look, make them more compact and take up less space than lamp-pumped systems. They are taking over in applications that were previously the reserve of conventional CO2 lasers and lamp-pumped solid-state lasers. At present, the main area of application for DPSSLs is material processing. They are now being used, for example, in the automobile industry for welding and cutting vehicle chassis.

About Osram Opto Semiconductors
Osram Opto Semiconductors GmbH, Regensburg, is a wholly owned subsidiary of Osram, one of the world’s three largest lamp manufacturers, and offers its customers a range of solutions based on semiconductor technology for lighting, sensor and visualisation applications. The company operates facilities in Regensburg (Germany), San José (USA) and Penang (Malaysia). In the 2002 fiscal year (to the end of September) its 3370 employees produced sales totalling EURO 309 million.

Further information is available at www.osram-os.com.

Pulse proof laser diodes from Osram Opto Semiconductors:
Laser diodes advancing into industryLaser diodes advancing into industry
Osram Opto Semiconductors has increased the pulse proof characteristics of its laser diodes by more than one order of magnitude. They have a laser threshold that is up to 25% lower and efficiency that is around 15% higher.

Press contact:

OSRAM

Marion Reichl
Tel: +49-941-850-1693
Fax: +49-941-850-4441693
Email: marion.reichl@osram-os.com