Improvement of axial resolution of spectral domain optical coherence tomography with wide band PLC splitter

We report the development and performance of high resolution spectral domain optical coherence tomography (SD-OCT) system based on 2×2 planar lightwave circuit (PLC) splitter that was designed as a single mode splitter at near infrared and used as the beam splitter for a SD-OCT system. The splitter has been made by coupling SMFs to a planar lightwave circuit (PLC) splitter chip. The PLC splitter chip was fabricated to have a single mode property with 740 nm cutoff wavelength and the SMFs, which have 730 nm cutoff wavelength, were securely connected to the PLC chip through fiber block arrays having lithographically fabricated V grooves. With the implemented PLC splitter, we have obtained a low excess loss of 0.4 dB at 840 nm with wide band coupling property. With the proposed 2×2 PLC splitter and fabricated WDM coupler, SD-OCT images of samples successfully obtained by using combined source with 840 nm and 880 nm SLDs.