I{11 {11 {11 {11 INVERTED LAMB DIP STABILIZED He-Ne LASER

Claim 2

the inner face of said first disc engaging said housing, and the plane of said inner face being perpendicular to said fixed axis, and

Claim 3

the plane of the outer face of said disc being inclined at an angle other than 90* to said fixed axis, b. a second rotatable disc rotatably mounted on said first disc and having an inner face continuously engaging and mating with the inclined outer face of said first disc and having an axis of rotation perpendicular to said first plane of said outer face of said first disc, and c. a cavity defining mirror disposed within said central bore of said first disc and fixed to said inner face of said second disc, such that, for at least one relative angular position of said first and second discs, the surface of said mirror is perpendicular to said axis of said laser cavity, so that, as said second disc is rotated through 180* for each angular position of said first disc, the angle between said laser cavity axis and said surface of said mirror is correspondinglY varied.

Claim 4

A method of accurately stabilizing the output laser beam wavelength of an He-Ne laser as defined in claim 2 wherein said referencing step comprises setting the frequency of the laser beam at the frequency of a hyperfine component of said inverted Lamb Dip.

Claim 5

A method of accurately stabilizing the output laser beam wavelength of an He-Ne laser as defined in claim 3 wherein the nominal output wavelength of the laser is 6328 A.

Claim 6

A laser as defined in claim 1 further comprising a housing enclosing said laser cavity, and a mirror position adjusting mechanism mounted on one end of said housing, said adjusting mechanism comprising: a. a first rotatable disc mounted on said housing for rotation about a fixed axis substantially coincident with the longitudinal axis of said laser cavity,

Claim 7

A laser device as defined in Claim 1 further comprising: a. a second resonant laser cavity; b. a second He-Ne laser gain cell and a second gaseous I2129 light absorption cell disposed optically in series within said second cavity, the optical axis of said second cavity being co-linear with the optical axes of said second gain cell and said second absorption cell; c. means for pumping said second gain cell for producing optical gain and oscillation; d. means for setting the frequency of the sustained oscillation of said second gain cell at the frequency of a second inverted Lamb Dip of gaseous I2129, thereby producing a second output laser beam having a second frequency stabilized about said second inverted Lamb Dip of gaseous I2129; and e. light detector means responsive to said first and second laser beams for producing an electrical signal having a frequency component equal to the difference between said first and second frequencies.

Claim 8

A laser device as defined in claim 6 wherein said first and second frequencies are in the 6328 A region.