Research On Axial Ranging Measurement System With Fourier Domain Low Coherence Interferometry

Cataract is a common eye disease which can be caused by many factors,the most direct consequence of the disease is the cloudy lens and visual axis,cause a greater impact on vision leading people blind.From now on science and technology,the method has still no effective drug treatment except intraocular lens transplant.Previous cataract surgery patient refers seeing something,but now patients are often hope that can see the objects clearly after surgery.For this reason,accurate preoperative visual axis parameter detection becomes very important.A low coherence interferometry is an emerging detection technology which has nondestructive,non-contact and high detection precision.The most important core component is the Michelson interferometer that is based on the broadband light source.First appeared low coherence interference is based on the time-domain interference system,its characteristic is to move the reference arm back and forth to match with the samples of different depth,but with the time domain method,there are still many shortcomings.First of all,it takes a long time and the precision is still not high enough.In recently years,the Fourier domain low coherence interferometry method is more and more popular,it is not only using the method of spectrum,and its detection speed is very fast.For some vibration or movement,it works very well.The Fourier domain low coherence interferometry will more and more widely used.Built on axial fast zoom Fourier domain of different position measurement in the coherence optical system,about the parts of the system are introduced,in order to achieve the purpose of rapid measurement,the system selects the fast linear array CMOS camera and lens are selected for the plated film lens of short infrared light to reduce unnecessary interference.By ZEMAX software the key light path can be arrange by reasonable design,make it possible to have a number of position measurements,and reduce the float in the reference arm.At the same time in order to get more reduce in the interference of other conditions,is also used in the experiment the sample and the reference model of the synchronous rotating arms.Finally,in view of the whole measuring system,we have a large number of experiments,including the simulation model,and the eye for the samples.By improving the signal-to-noise ratio of the interference image,improving the accuracy of detection,and changing focus from experiment.To justify the use of the feasibility of the method measuring intraocular parameters and still has great development potential.