A systematic comparison and evaluation of three different Swept-Source interferometers for eye lengths biometry

Abstract

This study reviews the development of Swept-Source interferometers and compares systematically three different Swept-Source interferometer designs for biometric measurements of the eye. Principles characteristics, conveniences and accessibilities of the three developed systems are presented.The main difference between the three Swept-Source systems is the method of tuning the wavelength at the broadband optical amplifier.The implementation of a “quasi-phase-continuous method” (QPC) for wavelength tuning led to longer measuring depth but was more time-consuming. The wavelength tuning using a rotating polygon mirror scanner was faster.The wavelength tuning via Fourier Domain Mode Locking (FDML), where the tuning frequency ft of the filter must be matched to the inverse cavity roundtrip time τ, achieved the widest tuning range combined with a rather better resolution and signal to noise ratio (SNR).The swept sources were compared using a fiber-optic based Michelson interferometer setup. Measurements of a self-made human model eye demonstrate excellent capturing of the biometric data, with all interfaces of eye optical components and their contours being clearly detected.