A Feasibility Study of Broadband White Light Emitting Diode (WLED) Based Full-Field Optical Coherence Microscopy (FF-OCM) Using Derivative-Based Algorithm

Developing cost-effective and fast detection methods in full-field optical coherence microscopy (FF-OCM) platform for biological applications is of prime focus today. In this paper, we report a cost-effective Linnik type FF-OCM system with a single broadband white light emitting diode (WLED) (470-850 nm, λ0 = 630 nm) light source in conjunction with a derivative-based image reconstruction algorithm. Sequential 2-D multiple phase-shifted interferograms were obtained by moving the sample stage using piezoelectric transducer and recorded via a 2-D charge complementary oxide semiconductor camera. Subsequently, the en-face sectional images were reconstructed using a derivative-based algorithm. The measured axial and lateral resolutions along with interferometric phase stability of the system were 0.9 μm, 1.4 μm, and 11 mrad, respectively. The advantages of the derivative-based algorithm over 4-step phase shifted method were demonstrated using USAF target and onion as test samples. Moreover, studies via the present system of the microstructure of skin epidermis in mouse ear with melanoma showed a significant deterioration from normal mouse skin in stratum corneum of the epidermis. This is the first study of the application of a derivative-based algorithm for biological samples in FF-OCM wherein WLED is used as a light source. The present system is stable, compact, and cost-effective compared to the conventional FF-OCM systems and provides comparable spatial resolution.