  We demonstrate a simple, compact, and cost-effective laser noise reduction
method for stabilizing an extended cavity diode laser to a 3x105 finesse mirror
Fabry-P\'erot (F-P) cavity corresponding to resonance linewidth of 10 kHz using
a crystalline MgF2 whispering gallery mode microresonator (WGMR). The laser
linewidth is reduced to sub-kHz such that a stable Pound-Drever-Hall (PDH)
error signal is built up. The wavelength of the pre-stabilized laser is tunable
within a large bandwidth covering the high reflection mirror coating of a F-P
supercavity.
