Source
Definition: Source is an optoelectronic element that delivers light (e.g. a laser or an LED). In fNIRS, it refers to a source of near-infrared light that is used to illuminate a tissue being interrogated. Sources can either require optic fibers to carry the light to source optodes placed on the scalp or can be integrated into optodes, wearable probes or modules placed directly on the scalp.
Alternative definition:
Synonym: emitter
References: https://doi.org/10.1146/annurev-psych-010213-115108https://doi.org/10.1016/S0006-3223(02)01550-0
https://doi.org/10.3390/s21186106
https://www.intechopen.com/chapters/28786
Related terms: detector, source-detector pair, channel, probe, diode