Stabilization of He/sub 2/(A/sup 3/. sigma. /sub u//sup +/) molecules in liquid helium by optical pumping for vacuum uv laser

Patent · Tue Aug 15 04:00:00 EDT 1978

OSTI ID:6444083

Fletcher, J C

A technique is disclosed for achieving large populations of metastable spin-aligned He/sub 2/(a/sup 3/..sigma../sub u//sup +/) molecules in superfluid helium to obtain lasing in the vacuum ultraviolet wavelength regime around 0.0800 ..mu..m by electronically exciting liquid (superfluid) helium with a comparatively low-current electron beam (100 to 200 keV), less than or equal to 10 ..mu..A) and spin aligning the metastable molecules by means of optical pumping with a modestly-powered (100 mW) circularly-polarized cw laser operating at, for example, 0.9096 or 0.4650 ..mu..m. Once a high concentration of spin-aligned He/sub 2/(a/sup 3/..sigma../sub u//sup +/) is achieved with lifetimes of a few milliseconds, a strong microwave signal destroys the spin alignment and induces a quick collisional transition of He/sub 2/(a/sup 3/..sigma../sub u//sup +/) molecules to the A/sup 1/..sigma../sub u//sup +/ state and thereby a lasing transition to the X/sup 1/..sigma..g/sup +/ state.

• Assignee: TIC; ERA-04-020065; EDB-79-031949
• Patent Number(s): US 4107627
• OSTI ID: 6444083
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
BEAMS
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EXCITATION
FAR ULTRAVIOLET RADIATION
FLUIDS
HELIUM 4
HELIUM II
HELIUM ISOTOPES
ISOTOPES
LASERS
LEPTON BEAMS
LIGHT NUCLEI
LIQUID LASERS
NUCLEI
OPTICAL PUMPING
PARTICLE BEAMS
QUANTUM FLUIDS
RADIATIONS
STABILIZATION
STABLE ISOTOPES
ULTRAVIOLET RADIATION