5 W continuous wave power, 0.81-μm-emitting, Al-free active-region diode lasers

Abstract

High power, 0.81-μm-emitting, semiconductor diode lasers are used as pump sources for Nd:YAG solid-state lasers. Devices (1-mm-long) consisting of a InGaAsP/In0.5(Ga0.9Al0.1)0.5P/In0.5(Ga0.5Al0.5)0.5P laser structure provide a threshold-current density, Jth, of 290 A/cm2 and a relatively high threshold-current characteristic temperature, T0 (140 K). Uncoated diode lasers (1.2-mm-long) have a maximum continuous wave output power of 5 W (both facets) at 20 °C. The internal power density at catastrophic optical mirror damage (COMD), P̄COMD, is determined to be 9.1 MW/cm2; that is, 1.8 times that for GaAs-active layer, Al-free, uncoated devices. Coated, InGaAsP-active devices are expected to have P̄COMD=18 MW/cm2, more than twice the P̄COMD of AlGaAs-active, 0.81-μm-emitting devices with the same emitting aperture. Therefore, 0.81-μm-emitting, InGaAsP-active diode lasers should operate reliably at powers at least twice those of AlGaAs-based devices with the same contact-stripe geometry.

InGaAsP/GaInP/AlGaInP 0.8μm QW lasers grown by MOCVD using TBP and TBAs

“…This is because the larger band gap of AlGaInP compared with that of GaInP can more effectively block the carrier overflow from the active layer to the cladding layer [5]. Therefore, Al-free active-region InGaAsP/GaInP/AlGaInP lasers have the advantages of both high reliability and good temperature characteristics [5][6][7][8]. InGaAsP/AlGaInP 0.8 mm lasers are usually grown by metalorganic chemical vapor deposition (MOCVD) or molecular beam epitaxy.…”

“…InGaAsP/AlGaInP 0.8 mm lasers are usually grown by metalorganic chemical vapor deposition (MOCVD) or molecular beam epitaxy. In the case of MOCVD growth [5][6][7], all the lasers are grown using highly toxic gas sources PH 3 and AsH 3 . Although InGaAsP infrared lasers [9,10] and AlGaInP red lasers [11][12][13] have been successfully grown using the less toxic liquid metalorganic sources tertiarybutylarsine (TBAs) and tertiarybutylphosphine (TBP), so far, there have been no reports on the growth of 0.8 mm InGaAsP/AlGaInP lasers by MOCVD using TBP and TBAs.…”

MBE growth of reliable high-power lasers with InGaAsP quantum well

“…Lasers with InGaAsP Al-free active region have shown strong advantages over conventional AlGaAs lasers due to their resistance to dark-line defects [5], and high threshold of catastrophic optical damage (COD) [6]. For 0.8 mm high-power lasers, reliability is a common concern.…”

“…Bournes et al from Coherent Inc. reported less than 1% degradation for 40 W laser bars during 1300 h operation at facet load of around 14 mW/mm at 25 C, which corresponded to a degradation rate of less than around 8 Â 10 À6 /h [8]. Most of semiconductor lasers with InGaAsP material system were grown in MOCVD or MOMBE (or CBE) [1,2,[4][5][6][7]. Recently solid source MBE systems with Pcracker were introduced to grow P-containing materials.…”

6.1 W continuous wave front-facet power from Al-free active-region (λ=805 nm) diode lasers

“…The internal power density at COMD, P COMD , is only 3 11 MW/cm 2 compared to about 18 MW/cm 2 expected for InGaAsP-active lasers emitting at 810 nm. 4 Therefore, a promising alternative has been to use Al-free InGaAsP/ InGaP/GaAs laser structures. Devices with InGaAsP active regions are intriguing because of their intrinsic resistance to the motion of dark-line defects, 5 much smaller facet temperature rises than AlGaAs-active uncoated devices, 6 and lower surface recombination velocity of InGaAsP compared to AlGaAs or GaAs.…”