Microarray selective epitaxy produces microlasers that emit at eight wavelengths
The Optoelectronics and High-Frequency Device Research Laboratories of Japan-based NEC Corp. report development of densely arrayed--pitched at 10 µm--semiconductor lasers with eight individually controlled lasing wavelengths. With an average wavelength of 1540 nm for the test, individual wavelengths were spaced less than 80 nm apart. Uniform output powers greater than 10 mW were obtained for all channels. Such devices could be important for wavelength-division-multiplexing applications.
The researchers produced the wavelength-selectable microarray laser diodes with a newly developed microarray-selective-epitaxy technique. They obtained uniform emissions from a chip with lasers spaced across a section 70 ¥ 400 µm. Fabrication involves making silicon oxide masks patterned so as to form eight-channel, 1-µm-wide window stripes spaced 10 µm apart. Multiple-quantum-well (MQW) waveguides are then selectively grown on these, and the bandgap energies of each MQW are controlled by changing the mask widths on both sides. If the widths are equal, the lasing wavelength distribution is uniform. The average lasing wavelength can be controlled by changing mask widths by the same amount. Contact: K. Kuodo at [email protected].