We present recent results on high-power, high-efficiency two-dimensional vertical-cavity surface-emitting laser
(VCSEL) arrays emitting around 808nm. Selectively oxidized, top-emitting single VCSEL emitters with 49% power
conversion efficiency were developed as the basic building block of these arrays. Because of the strong GaAs
absorption at the 808nm wavelength, the traditional bottom-emitting, substrate-emission configuration is not possible for
large arrays that require efficient heat dissipation. The processing and packaging challenges are discussed. We
demonstrate 3mm x 3mm arrays and 5mm x 5mm arrays with the GaAs substrate completely removed and mounted on
diamond submounts. These arrays emit more than 50W and 120W, respectively, and exhibit a maximum powerconversion
efficiency of 42%.
We present record output power levels (a few hundred Watts) in continuous-wave (CW) and quasi-CW (QCW) from 2D vertical-cavity surface-emitting laser (VCSEL) arrays, corresponding to power densities exceeding 1kW/cm2 in CW and 3.5kW/cm2 in QCW. These VCSEL arrays emit around 975nm with narrow spectral width (<1nm) and excellent wavelength stability (<0.07nm/K). Peak power conversion efficiency of properly designed arrays exceeds 50%. Additional features of these arrays include emission in a circular, low-diverging beam, and reliable high-temperature operation. These arrays can also be operated reliably in short pulses (<200nsec) at many times their roll-over CW current, making them useful for high-energy applications. VCSEL arrays with 2.2kW peak output power operating under 100nsec pulse-width have been demonstrated.
We review recent results on high-power, high-efficiency two-dimensional vertical-cavity surface-emitting laser
(VCSEL) arrays emitting around 980nm. Selectively oxidized, bottom-emitting single VCSEL emitters with 51% power
conversion efficiency were developed as the basic building block of these arrays. More than 230W of continuous-wave
(CW) power is demonstrated from a ~5mm x 5mm array chip. In quasi-CW mode, smaller array chips exhibit 100W
output power, corresponding to more than 3.5kW/cm2 of power density. High-brightness arrays have also been
developed for pumping fiber lasers, delivering a fiber output power of 40W. We show that many of the advantages of
low-power single VCSEL devices such as reliability, wavelength stability, low-divergence circular beam, and low-cost
manufacturing are preserved for these high-power arrays. VCSELs thus offer an attractive alternative to the dominant
edge-emitter technology for many applications requiring compact high-power laser sources.
We describe the parallel optical test of a photonic first-in-first-out (PFIFO) buffer memory based on flip-chip CMOS/SEED optoelectronic technology. The PFIFO detects pages of 4 by 8 binary bits, stores them in a 32 bit deep buffer memory, and transmits them in a 16 by 2 output modulator array. All 32 I/O and memory channels functioned, with an average input power of 40 microwatts and a minimum output contrast ratio of 2:1.