  We report a 65MHz-bandwidth triangular-shaped optical parametric oscillator
(OPO) for squeezed vacuum generation at 860nm. The triangle structure of our
OPO enables the round-trip length to reach 45mm as a ring cavity, which
provides a counter circulating optical path available for introducing a probe
beam or generating another squeezed vacuum. Hence our OPO is suitable for the
applications in high-speed quantum information processing where two or more
squeezed vacua form a complicated interferometer, like continuous-variable
quantum teleportation. With a homemade, broadband and low-loss homodyne
detector, a direct measurement shows 8.4dB of squeezing at 3MHz and also 2.4dB
of squeezing at 100MHz.
