News | May 8, 2001

New laser powers next-generation analytical instruments

Source: Coherent, Inc.
New laser powers next-generation analytical instruments

By Alan S. Brown

The first commercial solid-state 488-nm laser promises to usher in a new generation of analytical instruments. Introduced by Coherent Laser Div. (CLD; Santa Clara, CA) at the 2001 Conference on Lasers and Electro-Optics in Baltimore, MD, the semiconductor diode-pumped Sapphire 488-20 promises to free instrumentation from the limits of existing 488-nm air-cooled argon-ion lasers. The unit provides 20 mw of output power at 488 nm.

"For many years researchers and commercial companies have sought to exploit the power of diode-pumped solid-state laser technology at blue-green wavelengths," said Matthias Schulze, Product Line Manager for Coherent Laser Division.

"In particular, bio-instrumentation techniques have been based on air-cooled argon ion lasers that emit at 488 nm. But argon-ion lasers are large and electrically inefficient, and until now there has not been a solid-state equivalent.

"The all-solid-state SAPPHIRE exceeds the performance characteristics of air-cooled argon-ion lasers, while being 90% smaller, more reliable, more user-friendly and easier to service. With the inherent efficiency of diode-pumped technology, it consumes 98% less power and dissipates 98% less heat."

SAPPHIRE 488-20 is Coherent's first product in a class of Optically Pumped Semiconductor Lasers (OPSL) based on a special type of Vertical External Cavity Surface-Emitting Laser (VECSEL).

Specifically, while electrical current drives a conventional VCSEL, within an OPSL a semiconductor laser optically pumps the semiconductor gain medium (called the OPS chip).

At the heart of this proprietary OPS chip are quantum-well structures that provide gain at 976 nm. An intracavity frequency-doubling crystal converts the emission to the desired 488 nm wavelength. SAPPHIRE produces a TEM00 beam profile and optical noise less than 0.25% rms.

"Although SAPPHIRE is new, it is an assembly of proven subcomponents, all of which have well-quantified performance characteristics," said Schulze. "Moreover, mature technologies such as our semiconductor growth process and clean-room robotic assembly will enable Coherent to produce very robust 488-nm lasers for applications ranging from bio-instrumentation and digital imaging to printing and inspection."

Added Schulze, "SAPPHIRE is a breakthrough for OEM integrations. It is a milestone in laser technology that will produce a new era of user-friendly, compact, efficient and reliable instruments. Our beta testing phase was successfully finished early this year and SAPPHIRE production is set to fulfill fast-growing market demands."

Founded in 1966, Coherent, Inc. is a Standard & Poor's SmallCap 600 company and a world leader in providing photonics-based solutions to the commercial, scientific, medical, and telecom markets.

Please direct any questions to Matthias Schulze, Coherent Product Line Manager at +49 451 3000 303 or Paul Ginouves, Business Development Manager for Coherent's Instrumentation Business Unit at (408) 764 4650.

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