Entries from:

PAC, 2007, 79, 293. Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006), doi:10.1351/pac200779030293

α-cleavage (alpha-cleavage)
α-elimination
absorbed (spectral) photon flux density
absorbed (spectral) radiant power density
actinic
actinism
acyl shift (1,2-, 1,3-, photochemical)
alkene photocycloaddition
alkene photodimerization
alkene photoisomerization
alkene photorearrangement
AM 0 sunlight
AM 1 sunlight
amalgam lamp
aromatic photocycloaddition
asymmetric photochemistry
aza-di-π-methane rearrangement
bicycle rearrangement
bicycle-pedal (BP) mechanism
biphotonic excitation
biphotonic process
bipolarons
branching plane
Brewster angle,
brightness
brightness of a laser dye
chemically induced dynamic electron polarization (CIDEP)
chemically initiated electron exchange luminescence (CIEEL)
color scale
colourability
complete active space self-consistent field (CASSCF)
complete active space self-consistent field second-order perturbation theory (CASPT2)
computational photochemistry
concentration depolarization
conical intersection
continuous wave (CW) laser
conversion cross-section
crystal photochemistry
cut-on filter
DAS
Dauben–Salem–Turro rules
de Mayo reaction
di-π-methane rearrangement
di-π-silane rearrangement
dichroic filter
dichroic mirror
dichroism
diradicaloid
dose
downconversion
driving force (for electron transfer)
Drude–Nernst equation (for electrostriction)
dual fluorescence of systems or molecular species
dual-mode photochromism
E/Z photoisomerization
El-Sayed rules
electron back-transfer
electrostriction
emission anisotropy
entrainment in photochemistry
excimer lamp
exposure in photochemistry
fatigue of a photochromic system
fluence rate,
fluorescence lifetime
fluorescence resonance energy transfer
fluorogenic
fluorophore
Förster-resonance-energy transfer FRET
Fourier-transform spectroscopy
frequency, , in photochemistry
frequency-domain fluorometry
FRET
gated photochromism
geminate ion pair
Gibbs energy of photoinduced electron transfer
global analysis
half-life, , of a transient entity
half-life, , of a photochromic system
heliochromism
hula-twist (HT) mechanism
hyperfine (interaction)
IC
ICT
ICT emission
infrared
intersection space
intramolecular charge transfer, (ICT)
irradiance (at a point of a surface),
ISC
isolampsic point
isooptoacoustic point
isosbestic point
isostilbic point
Jahn–Teller effect
Kasha rule
LADS
Landau–Zener model
LAS
laser dye
laser-jet photochemical technique
LED
lifetime,
light polarization
light-emitting diode (LED)
linear dichroism (LD)
planar intramolecular charge transfer (PICT)
polaron
self-localized excitations in conjugated organic polymers
spectral sensitivity,
twisted intramolecular charge transfer (TICT)