Flip-chip bonding produces multiple-wavelength emitters

While continuing efforts toward development of a continuous-wave, blue-output diode laser based on gallium nitride (GaN), researchers at the Xerox Palo Alto Research Center (PARC; Palo Alto, CA) have demonstrated the ability to include GaN in a multiple-wavelength emitter by using flip-chip bonding. Wavelengths emitted from the PARC device included laser light at 825 and 675 nm from a gallium arsenide (GaAs) based chip, as well as 420 nm from a GaN-based light-emitting diode.

Flip-chip bonding produces multiple-wavelength emitters

While continuing efforts toward development of a continuous-wave, blue-output diode laser based on gallium nitride (GaN), researchers at the Xerox Palo Alto Research Center (PARC; Palo Alto, CA) have demonstrated the ability to include GaN in a multiple-wavelength emitter by using flip-chip bonding. Wavelengths emitted from the PARC device included laser light at 825 and 675 nm from a gallium arsenide (GaAs) based chip, as well as 420 nm from a GaN-based light-emitting diode.

The red- and infrared-output lasers were fabricated monolithically by removing portions of a red-output, gallium indium phosphide laser and selectively regrowing an infrared laser structure. The blue-output GaN emitter was added to the GaAs structure by flip-chip bonding, in which photolithographic placement of solder bumps on both chips provided alignment tolerances on the order of 2 µm. As GaN technology develops to the point of delivering blue- and green-emitting diode lasers, the Xerox team expects this bonding method to allow placement of all three laser beams for a full-color scanning system onto a single wafer--providing both precise alignment at the device level and the ability to route all three beams through a single optical system.

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