Vertical-cavity surface-emitting lasers (VCSELs) have been used to opticall
y pump a planar-cavity, Nd:YVO4 Microchip laser. Lasing was achieved with a
minimum pump power of 0.8 mW from a 10 mum diameter, circular aperture VCS
EL. The microchip laser operates in a fundamental Gaussian mode of 40-50 mu
m diameter for a range of pump sizes from 10 to 50 mum with a threshold pum
p power proportional to the pump size. These characteristics indicate that
the mode formation is controlled by gain-induced refractive index changes w
ithin a cavity that is positively detuned from the atomic resonance. Stable
, Gaussian mode formation is also achieved when directly pumping the microc
hip lasers with no intervening optics. (C) 2001 Elsevier Science B.V. All r
ights reserved.