Q-Switched Raman laser system

Claim 3

The method according to claim 1, further including the step of providing He gas having atomic numerical density of substantially N=3×10 16 cm -3 and absorber length substantially L A =1 cm as said saturable absorber.

Claim 4

A method according to claim 1, further including the step of providing a solid coating of CaO on said first optical cavity end mirror as said saturable absorber, with the CaO having atomic numerical density substantially N=3×10 20 cm -3 and absorber length substantially L A =1 μm.

Claim 5

A method according to claim 1, further including the step of providing a Th-doped alkali halide gas having atomic numerical density of substantially N=3×10 16 cm -3 and absorber length L A =1 cm as said saturable absorber.

Claim 6

Apparatus for producing a pulse of laser radiation of frequency ν=ν 0 +Δν S , the apparatus comprising: an optical cavity bounded by two end mirrors substantially parallel and facing one another, at least one of which is substantially 100% reflecting at a predetermined frequency ν=ν 0 ; a broadband saturable absorber positioned within the optical cavity and adjacent to one of the end mirrors; an energy storage laser amplifier, positioned within the optical cavity between the saturable absorber and the second end mirror, the amplifier being capable of amplifying radiation of frequency ν=ν 0 ; a Raman cell having at least two sidewalls, positioned in the optical cavity between the saturable absorber and the second end mirror, and containing a Raman-active gas that is excited by passage therethrough of radiation of frequency ν=ν 0 and emits that radiation at the first Stokes or anti-Stokes frequency ν=ν 0 +Δν S corresponding to excitation at frequency ν=ν 0 , the cell having at least one sidewall that is substantially transparent to radiation of frequency ν=ν 0 +Δν S ; seed pulse means to produce and introduce a radiation pulse of frequency ν=ν 0 into the optical cavity so that this pulse propagates from one cavity end mirror to the other cavity end mirror; Stokes pulse means, positioned adjacent to the Raman cell to produce a radiation pulse of frequency ν=ν 0 +Δν S and to direct this pulse through at least one Raman cell transparent sidewall in timed relationship with passage of the radiation pulse of frequency ν=ν 0 through the Raman cell; and a mirror that is substantially fully reflecting to incident radiation at frequency ν=ν 0 +Δν S , positioned adjacent to one of the transparent sidewalls of the Raman cell so that radiation from the radiation source passes through the Raman cell once, is reflected at perpendicular incidence by this mirror and passes through the Raman cell a second time.

Claim 7

Apparatus for producing a pulse of laser radiation of frequency ν=ν 0 +Δν S , the apparatus comprising: an optical cavity bounded by two end mirrors substantially parallel and facing one another, at least one of which is substantially 100% reflecting at a predetermined frequency ν=ν 0 ; a broadband saturable absorber positioned within the optical cavity and adjacent to one of the end mirrors; an energy storage laser amplifier, positioned within the optical cavity between the saturable absorber and the second end mirror, the amplifier being capable of amplifying radiation of frequency ν=ν 0 ; a Raman cell having at least two sidewalls, positioned in the optical cavity between the saturable absorber and the second end mirror, and containing a Raman-active gas that is excited by passage therethrough of radiation of frequency ν=ν 0 and emits that radiation at the first Stokes or anti-Stokes frequency ν=ν 0 +Δν S corresponding to excitation at frequency ν=ν 0 , the cell having at least one sidewall that is substantially transparent to radiation of frequency ν=ν 0 +Δν S ; seed pulse means to produce and introduce a radiation pulse of frequency ν=ν 0 into the optical cavity so that this pulse propagates from one cavity end mirror to the other cavity end mirror; Stokes pulse means, positioned adjacent to the Raman cell to produce a radiation pulse of frequency ν=ν 0 +Δν S and to direct this pulse through at least one Raman cell transparent sidewall in timed relationship with passage of the radiation pulse of frequency ν=ν 0 through the Raman cell; and a mirror that is substantially fully reflecting to incident radiation at frequency ν=ν 0 +Δν S , positioned adjacent to one of the transparent sidewalls of the Raman cell so that radiation from the radiation source passes through the Raman cell once, is reflected at perpendicular incidence by this mirror and passes through the Raman cell a second time.

Claim 8

Apparatus according to claim 5, wherein said two optical cavity end mirrors are not axially aligned relative to one another and said Raman cell has two endwalls, each endwall having an endwall mirror, with the two Raman cell endwall mirrors being parallel to one another and being oriented so that a radiation pulse that is perpendicularly incident upon one of said optical cavity end mirrors will be serially reflected thereat, reflected by one of the Raman cell endwall mirrors, reflected by the second Raman cell endwall mirror and proceed toward said second optical cavity end mirror at perpendicular incidence.

Claim 9

Apparatus according to claim 6, wherein said saturable absorber includes He gas having atomic numerical density of substantially N=3×10 16 cm -3 and absorber length substantially L A =1 cm.

Claim 10

Apparatus according to claim 6, wherein said saturable absorber includes a solid coating of CaO on said first optical cavity end mirror, with the CaO having atomic numerical density substantially N=3×10 20 cm -3 and absorber length substantially L A =1 m.

Claim 11

Apparatus according to claim 6, wherein said saturable absorber includes a Th-doped alkali halide gas having atomic numerical density of substantially N=3×10 16 cm -3 and absorber length substantially L A =1 cm.