Fig. 1.

Diagram of dual modality set up. Surface magnifying chromoendoscopy (SMC, 638-nm laser diode) and optical coherence tomography [OCT, 890-nm center wavelength superluminescent diode (SLD)] sources are fiber coupled into endoscope. A long-wave pass (LWP) filter is used to reflect excitation light and pass emission light in the SMC proximal setup, while neutral density (ND) filters attenuate OCT source power. Charge-coupled devices (CCD) are used to detect signal in each modality, and data is electronically transmitted to the central processing unit (CPU).