I believe this answer is innacurate. Our Litton-92 INS has laser gyros. It is used to power one of the aircraft ADI's as well.
http://www.irconnect.com/noc/press/p....mhtml?d=16594
To quote "The Litton LTN-92 system is an ARINC 561 strapdown INS with full ARINC 704 digital interface capability. The LTN-92 uses state-of-the-art ring laser gyroscopes and is the ideal choice for replacement of earlier, low reliability "spinning wheel" inertial systems."