Abstract:
Presented is an optical coherence tomography system and method to increase imaging depth of optical coherence tomography (OCT) by selective amplification. In a swept-source OCT system with periodically linear wavenumber-vs-time characteristic, the signal in principle is summation of various sinusoidal signals with different frequencies. Each frequency component of the recorded signal carries reflectivity information for a certain depth of the analyzed object. At greater depth inside the analyzed object, the reflectivity information is generally weak due absorption and scattering. An analog or digital electronic circuit selectively filters and amplifies frequencies above some threshold, possibly up to another threshold. In this way, even small signals for relatively larger depths become detectable.