Lw. Tu et al., IN-VACUUM CLEAVING AND COATING OF SEMICONDUCTOR-LASER FACETS USING THIN SILICON AND A DIELECTRIC, Journal of applied physics, 80(11), 1996, pp. 6448-6451
We propose and demonstrate a novel approach to the coating of semicond
uctor laser facets. In this approach, processed semiconductor lasers a
re cleaved in a high-vacuum system immediately followed by coating of
the vacuum-exposed facet with a very thin Si layer (less than or equal
to 100 Angstrom) and a large band gap dielectric (Al2O3) layer. The S
i layer is sufficiently thin to avoid the formation of quantized bound
states in the Si. GaAs coated with thin Si and Al2O3 have a higher lu
minescence yield and a lower surface recombination velocity than bare
GaAs surfaces as well as GaAs surfaces coated with Al2O3 only. A surfa
ce recombination velocity of 3x10(4) cm/s has been obtained using a mo
dified dead layer model for the Si/Al2O3 sample. It is also shown that
lasers which are cleaved in vacuum and subsequently coated with Si an
d Al2O3 have improved properties including an increased threshold for
catastrophic optical damage. (C) 1996 American Institute of Physics.