Young Ju Yun {I am not a specialist, just interested} In papers I have edited the spectroscopic method(s) used have been confounded with a number of abbreviations, so you may need to widen your search. I have encountered numerous and often misused / overlapping combinations of:

• transient absorption (TA) spectroscopy (TAS)
• nanosecond TA (nsTA)
• femtosecond transient absorption spectroscopy (FTAS) (fsTA)
• ultrafast (femtosecond) transient absorption spectroscopy (UFTAS)
• and mixtures of the above descriptions using aka: ’flash photolysis’ & technique based names such as “pump-probe” spectroscopy

These may be of use, (or maybe widely off topic:

• A.P. Darmanyan, Generation of 1O2 and the mechanism of internal conversion in 9,10-diphenylanthracene, Chemical Physics Letters, Volume 91, Issue 5, 1982, Pages 396-400, ISSN 0009-2614, https://sci-hub.st/10.1016/0009-2614(82)83308-3
• A. Maciejewski, R.P. Steer, Spectral and photophysical properties of 9,10-diphenylanthracene in perfluoro-n-hexane: the influence of solute—solvent interactions, Journal of Photochemistry, Volume 35, Issue 1, 1986, Pages 59-69, ISSN 0047-2670, https://sci-hub.st/10.1016/0047-2670(86)87117-9

Cheers,

Leo

Young Ju Yun , please give the title of your question in Google scholar and you will obtain a lot of hits.

Among them , read the joined pdf and see page 2 (experimental part about Fs_TA.

you can search with :

https://libraries.catholic.edu/research-help/how-do-i/google-scholar.html

too.

Good luck

JRG