Three-Dimensional Pupillography Using Optical Demultiplexer-OCT at a Speed of 1,000,000 Axial Scans Per Second

Abstract

Purpose: : To evaluate three-dimensional pupillography using optical demultiplexer-OCT (OD-OCT).

Methods: : Our OD-OCT system utilizes super luminescent diode (SLD), developed at NTT Electronics. The output light from the SLD is amplified with a semiconductor optical amplifier (SOA) and divided into the sample arm (50%) and the reference arm (50%) by the coupler. In the sample arm, an attenuator is used to adjust the power illuminating the sample to be 4.5mW. The sample arm light is directed onto the sample with a collimator lens and an objective lens. A part of galvano-mirrors are used to scan the light beam on the sample. Backscattered or backreflected light from the sample is collected with the light illuminating optics and directed to SOA with an optical circulator. The laser probe was mounted on a slit-lamp base. Seven normal subjects were examined in the sitting position.

Results: : The OD separates light at equal frequency interval of 25GHz on 320 channels, the frequency of the center channel being 285THz (1052nm), which enables OD-OCT to provide an axial resolution of less than 12µm in the ocular tissue. Seven pupils in eyes of seven normal patients were imaged.

Conclusions: : This technique enables spontaneous pupillary oscillation while simultaneously maintaining the full capability of high-speed volumetric OD-OCT functionality.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • motion-3D • pupillary reflex