Real-time stroboscopic full-field optical coherence tomography based on graphics processing unit

We present the real-time stroboscopic full-field optical coherence tomography (FF-OCT) system that is based on graphics processing unit (GPU). The basic configuration of the proposed FF-OCT system was the Linnik interferometer. While scanning of a reference mirror in the axial direction, a series of the transverse sectional image was captured with a 2-dimensional CCD camera. To get a depth-resolved 3-D image, the light source of OCT was turned on and off like a stroboscope at the Doppler frequency of the OCT system. The CCD camera used in experiment operated at a rate of 200 frames per second, but the Doppler frequency was similar to kHz. To overcome the slow operation of the CCD camera below the Doppler frequency, the light source was operated in the stroboscopic mode. In addition, lock-in detection technique was utilized in order to avoid the dissolution of the coherent signals during the integration time of the CCD camera. Furthermore, the Doppler frequency shift due to nonlinear scanning motion of the reference mirror was monitored by using an auxiliary interferometer and then fed back to the light source driver so that the strobe frequency was always matched with the Doppler frequency of the OCT system. For the real-time 3-D rendering, we used a graphics processing unit.