Abstract: 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 (100-200keV, .ltorsim.10.mu.A) and spin aligning the metastable molecules by means of optical pumping with a modestly-powered (100mW) 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.