Coherent Continues Strategic Buys in Semiconductor Laser Market

Kathleen G. Tatterson

SANTA CLARA, Calif. -- Coherent Inc., acquiring the pieces it believes are necessary to unlock the puzzle that is the laser market's future, followed up its purchase of Finnish wafer maker Tutcore with the acquisition of microchip-laser manufacturer Micracor Inc. of Acton, Mass.
Coherent gained worldwide exclusive rights to more than 15 core patents on Micracor's technologies.
The company began strategically picking up the pieces when it bought Amoco and Adlas two years ago as well as Uniphase's semiconductor operations to bolster its diode laser operations, and its processing and packaging know-how.
"The technology is moving toward solid-state lasers," said Bernard Couillaud, Coherent's CEO and president. "We started with flashlamps, then diode-pumped lasers, and the next step is the solid-state. We need to be ready for that."
One part that was missing from the company's plan was wafer growth. Coherent found Tutcore's aluminum-free wafers, manufactured using molecular beam epitaxy, to be the most suitable for laser-diode fabrication. "By acquiring [Tutcore], we will have the missing piece to producing semiconductor lasers," Couillaud added. (See "Coherent Expands with Purchase of Finnish Wafer Processor Stock," Photonics Spectra, January 1997, p. 16.) Besides offering Coherent the opportunity to tailor the diode laser to a given diode-pumped solid-state laser, the acquisition will allow the company to control the manufacturing process from start to finish, he said.

A $200 million market
Coherent had been working with Tutcore on developing and producing aluminum-free epitaxial wafers for semiconductor lasers. Coherent estimates the market for such diodes at $200 million for telecommunications, materials processing, printing, medical and solid-state laser-pumping applications.
Couillaud said that the Micracor purchase will help Coherent in both the diode-pumped solid-state and semiconductor laser markets. Micracor's diode-pumped microchip laser will address the low-power market up to 100 mW and should lend itself to high-volume, low-cost manufacturing.
Coherent's products will also benefit from the high-power, high-quality, single-frequency operation of Micracor's optically pumped semiconductor technology. This advantage will help Coherent's products in telecommunications and scientific applications.
Although tight-lipped about the company's strategy on the telecommunications front, Couillaud said that the microchip diode-pumped solid-state laser will find its market as a transmitter at wavelengths from 1.3 to 1.5