Enhanced deep tissue imaging using long wavelength conjugate spectral domain OCT with balanced detection

Deep tissue imaging is achieved with a long-wavelength conjugate SD-OCT (Spectral-Domain Optical Coherence Tomography) combined with balanced detection. The use of long wavelength and conjugate configuration serves to reduce scattering and counteract spectrometer roll off, respectively, in SD-OCT, thereby enhancing imaging depth. A 1550nm OCT system is designed with the use of supercontinuum source (SuperK FIANIUM FIU-6 OCT) and Cobra 1600 spectrometer with bandwidth 1450-1690 nm. Balanced detection is employed to mitigate the excess noise associated with the supercontinuum source and to minimize the autocorrelation noise artefacts. This advanced technique leveraging long wavelength and BD in conjugate SD-OCT has allowed us to achieve optical imaging depths exceeding 4 mm in chicken breast tissue and scotch tape.