Scale factor improvement for angular velocity measurement based on an optoelectronic oscillator. 
A scheme of angular velocity measurement with an improved scale factor is proposed and experimentally demonstrated based on the joint operation of a Sagnac loop and an optoelectronic oscillator (OEO).  In this scheme, the Sagnac-induced phase difference is mapped into the oscillating frequency shift of the OEO with a large scale factor by making one of the two counter-propagating signals in the Sagnac loop carrier-suppressed modulated and the other just travel through the modulator.  The cascaded Sagnac loop and OEO structure can further improve the scale factor by setting a long Sagnac loop and a short OEO loop independently.  A sensitivity scale factor as high as 742 kHz/(rad/s) is obtained in our experiment.