Specifications include, but are not limited to: 1. Cavity Stabilized Laser at 698.45 nm, with capability to lock user-provided laser at 689 nm to same cavity. 1 a. >10 mw output power at 698.45 nm linearly polarized laser light provided at output of FC/APC terminated polarization maintaining fiber. 1 b. <1 Hz laser line width (see next lines). 1 c. <8 x 10-16 Allan deviation at 1 second, characterized by vendor before shipment. 1 d. <45 kHz drift over 24 hours. 1 e. <150 Hz frequency excursion after linear drift cancellation over 24 hours. 1 f. Cavity finesse > 200,000. 1 g. Cavity length >10 cm. 1 h. Vacuum can, vibration, acoustic, thermal isolation, PDH optics and lock box provided, cavity temperature stabilized to ULE zero-crossing temperature. 1 i. Additional fiber coupled input into cavity to simultaneously stabilize 689 nm light to the cavity. This would include all optics necessary to stabilize laser to cavity. EOM and PDH lock box for 689 nm light desired as options but not required.