SPECTROSCOPY OF NEGATIVE-IONS UTILIZING MULTIPHOTON DETACHMENT IN A RAMAN COUPLING REGIME

Multiphoton detachment of Te- is studied utilizing two optical fields of wavelengths approximately 694 nm and approximately 1064 nm, respect ively. Three-photon detachment is resonantly enhanced when the Raman c ondition is satisfied for coupling of the Te- 5p5 P-2(3/2) and P-2(1/2 ) fine-structure states. The fine-structure splitting is determined to be 5004.7 +/- 0.2 cm-1, which represents a 25-fold improvement over e arlier measurements. The possibilities for extended spectroscopic meas urements, as well as general perspectives for multiphoton experiments at high intensities, are briefly discussed.