Optical pumping of PH
3with a CO
2TEA laser has yielded 44 far IR lasing lines in the

m region. A table of energy levels for the ground state ν
2and ν
4has been compiled which has permitted the assignment of 16 absorption matches and 40 laser lines. Four of the laser lines appear to have high gain and lase, single pass with CO
2mode-locked pumping.