Application of an InGaAsP diode laser to probe photodissociation dynamics: I* quantum yields from n- and i-C3F7I and CH3I by laser gain vs absorption spectroscopy

A room temperature heterostructure InGaAsP laser diode operating at 1315 nm is employed for the first time for detection of I*(2P1/2) and I(2P3/2) atoms. The cw diode probe laser is used to study I* yields in the photodissociation of n- and i-C3F7I and CH3I by the new technique of time-resolved laser gain vs absorption spectroscopy. Preliminary quantum yields determined at 266 nm for n-C3F7I, i-C3F7I, and CH3I are 102±4%, 102±7%, and 73±4%, respectively. With further refinements to the diode laser set-up, highly accurate quantum yields will be possible.