OPTICAL DELAY

Hello sarath,
It is about bidirectionality. You need to increase the number of iterations to get an output signal. Please refer to the lesson 5 of the tutorial that optiwave has provided. i am attaching it please find it herein. it would definitely help you in getting a clear idea about different aspects of using different bidirectional components. I hope it helps.
Regards

hello sarath chandran
i think the topic was discussed in earlier posts as on link

Bidirectional Optical Fibers

Bidirectional optical fiber

http://www.eqtel.psut.edu.jo/Project/Puplications/fiber%20optic%20bi-directional%20communication.pdf

hope it helps

even a small length can also acts as delay
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&uact=8&ved=0ahUKEwjTxqD-lMLMAhWTco4KHexUB_4QFghEMAY&url=http%3A%2F%2Frfoptic.com%2Fproducts%2Foptical-delay-line%2F&usg=AFQjCNFQtka7ogNk8twGNLnO-QPmGhuvEQ&sig2=4OFZjNOPTxFlQoEobJ_hlg&bvm=bv.121099550,d.c2E
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&cad=rja&uact=8&ved=0ahUKEwjTxqD-lMLMAhWTco4KHexUB_4QFghLMAc&url=http%3A%2F%2Fultrafastsystems.com%2Foptical-delay-line%2F&usg=AFQjCNGlvOlxMvTYKBZyVYc8xvkTAFczqQ&sig2=OEHCKUJr1edDJAlubNpgqw&bvm=bv.121099550,d.c2E
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=11&cad=rja&uact=8&ved=0ahUKEwje8pyulcLMAhWKHY4KHQUrBJ04ChAWCCAwAA&url=http%3A%2F%2Fwww.mesaphotonics.com%2Fproducts-2%2Foptical-delay%2F&usg=AFQjCNFlKIrqKiZnfdolyyeVIeKLamsDFw&sig2=B1jtG-N4thTmxPcZ00ymtQ&bvm=bv.121099550,d.c2E
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=16&cad=rja&uact=8&ved=0ahUKEwje8pyulcLMAhWKHY4KHQUrBJ04ChAWCD8wBQ&url=http%3A%2F%2Fwww.m2optics.com%2Fblog%2Fbid%2F70587%2FCalculating-Optical-Fiber-Latency&usg=AFQjCNE8-ZbuntMMUFaJiM5KDSR9hGub-Q&sig2=nJuMCYZB0oeM39Sv3N2e-Q&bvm=bv.121099550,d.c2E
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=18&cad=rja&uact=8&ved=0ahUKEwje8pyulcLMAhWKHY4KHQUrBJ04ChAWCEswBw&url=https%3A%2F%2Fwww.osapublishing.org%2Fabstract.cfm%3Furi%3Doe-18-3-3093&usg=AFQjCNEi-CfdwVo8EUo9gvUb2hH87eq1sw&sig2=Q-tMcjABO8ok30IXJkccGg&bvm=bv.121099550,d.c2E

Hi Sarath,
I think you must use circulator of which delay is attached to it iin its 2nd port.
It will work.

Thanks,

Hello,
I agree to most of points. I want to add that An optical delay line is a critical element of any ultrafast pump-probe (or pump-gate) set-up. Even a small change in the beam pointing (laser beam drift, moved mirrors, etc.) can compromise the quality of your data. This is why it is recommended to check the delay line alignment at least once a day. Alignment of the delay line normally requires special technical training and can be time consuming. Our patent pending Smart Delay Line™ system fully restores the original alignment of your delay line in a few minutes. Very importantly, the original beam pointing after the delay line gets restored as well. This ensures that the optical setup “downstream” from the delay line will not require re-alignment. This significantly shortens the time needed to set up an experiment allowing for more up-time of the instrument.
Hope this helps you.
Thanks

Hi
I am attaching link of a paper. Refer to it i hope it will be helpful
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-18-3-3093
It discusses tunable optical delay line based on the use of a single chirped fiber Bragg grating written into a standard single mode optical fiber. It proposes scheme, the delay is induced through the Bragg grating differential group delay curve. This is achieved by launching orthogonally polarized optical pulses in both directions into the Bragg grating and by controlling its local birefringence. This bidirectional propagation allows to compensate the second-order dispersion. The setup is suitable to delay pulses with a spectral width just less than the grating reflection bandwidth, which is particularly useful in the context of forthcoming wavelength division multiplexing ultra-high bit rate lightwave systems. In this work, the performances of the setup are investigated using a pulsed laser delivering 6.3 ps Fourier transform limited pulses at 1548 nm. A maximum delay of 120 ps (about 20 times the pulse width) is reported experimentally.
Regards

Hello Everyone,
I would recommend everyone to please refer to to the lesson 5 of the tutorial that optiwave has provided it would definitely help you in getting a clear idea about different aspects of using different bidirectional components. I have provided the pdf file as well. You can go through it. Thanking you
Regards