  Squeezed vacuum states enable optical measurements below the quantum limit
and hence are a valuable resource for applications in quantum metrology and
also quantum communication. However, most available sources require high pump
powers in the milliwatt range and large setups, which hinders real world
applications. Furthermore, degenerate operation of such systems presents a
challenge. Here, we use a compact crystalline whispering gallery mode resonator
made of lithium niobate as a degenerate parametric oscillator. We demonstrate
about 1.4 dB noise reduction below the shot noise level for only 300
$\mu\text{W}$ of pump power in degenerate single mode operation. Furthermore,
we report a record pump threshold as low as 1.35 $\mu\text{W}$. Our results
show that the whispering gallery based approach presents a promising platform
for a compact and efficient source for nonclassical light.
