Time-domain (TD-) OCT systems, require SLEDs with good spectral shape, for example first-order Gaussian, such that the coherence function features good sidelobe suppression. Axial or depth scanning is achieved by moving the reference mirror. The optical detector is a simple photodiode (PD) or photoreceiver that is connected to a data acquisition (DAQ) card, which is sampling the OCT signal and forwarding the data to a host PC. TD-OCT is typically limited to a few kHz, which is why time-domain have been replaced in many medical applications by faster and more sensitive Fourier-domain systems.

The detector is mainly composed of a fast and stable OCT system, which consists of OCT host with sealed optical and hardware system and external computer or touch screen for system control. The host includes: optical system, hardware system and software system. Broadband SLD is used as the light source, and ultra-high speed high-resolution spectrometer is used to collect the spectral signal. The operation software mainly includes light source control software and data acquisition software.