OCT Monte-Carlo simulation model based on confocal mode is used to study the reflectivity of back-scattering light from high scattering tissue in OCT system

the simulation result shows that the intensity of useful back-scattering light for OCT imaging is about 10

-8

~10

-10

of incidence light. The weak but useful signal limits the OCT imaging speed

detection sensitivity

signal-to-noise ratio and image contrast. Therefore

a new special coating beam splitter was devised. As a result

firstly by enhancing the output power of lamp-house to a large possible degree while being assure that tissues are not scathed

the new coating beam splitter causes the intensity of referential light to be reduced by four orders

and the output power of electrophotonic detector can not easily reach saturation. Secondly

the intensity gap between referential and signal beam is largely reduced

and image intervening contrast is increased by two orders. In spite of imaging at high speed

OCT system yet has qualified images. Thirdly

specially designed system renders sample arm with most intensive light and lessens the loss of back-scattering light to the least degree

therefore

signal-to-noise ratio improves by 6 dB and detection sensitivity of the system increases to 43 dB by actual sample test.