OCT Technologies: Swept Source vs. Spectral Domain

[@yizhou866]

Thanks for your helpful presentation! Always great!

[@thorlabs]

We’re glad it was helpful!

[@TheSandkastenverbot]

Thanks a lot for this very informative presentation!

[@aatt3209]

thank you so much for this informative & wonderful presentation.

[@thorlabs]

We’re glad you liked it!

[@ajit_edu]

Nice work. I was looking for this depth but simple presentation. One question - in TD OCT does the scanning of reference arm along axial direction and sample arm in lateral happen simultaneously at the same time ? Or we scan the reference arm to desire depth, keeping sample atr fixed, and repeat this process again?

[@thorlabs]

A full scan of the reference arm happens at every lateral position. This gives you the full depth information (A-scan) at an individual lateral position. You then move to the next lateral position and repeat the scan of the reference arm to obtain the next A-scan.

[@ajit_edu]

8.04 at SD OCT, how do get the depth information ? How k is converted to z? Again at 9.39 how do we get z from k doing Fourier? After Fourier we get intensity vs lambda/2pi, where is z?

[@thorlabs]

The Fourier transform of the interference pattern in k-space gives us the time delay between the two echoes that generated the interference pattern. Taking into account the speed of light in the medium we can calculate the path length difference between the echoes.

[@ajit_edu]

@@thorlabs Thank you. for your response. is k=1/lambda or 2*pi/lambda ?

[@thorlabs]

We use k=2*pi/lambda.

[@333bctan]

will ss oct take over sd oct and why only topcon is in the ss oct technology front ?

[@thorlabs]

Thank you for your questions! We have observed a hype for SS-OCT in recent years. In our opinion, both technologies offer advantages for certain applications. SS-OCT offers great speed and power, which makes it an attractive solution for many applications today; however, SD-OCT offers the advantage of a higher axial resolution. Hence, whenever high axial resolution is crucial, SD-OCT will keep playing an important role. Topcon is not the only company working with SS-OCT technology; other companies are working with it too.