Consider the scenario,
input pulse width and spectrum = 700fs/ 2.23nm (after propagating thru 20cm SMF)
Output pulse width and spectrum become = 1.183 ps/ 38.357nm
How to select a compressor (Grating pair or the one more suitable) to compress output pulse with of 1.183ps to its fourier limit.
Muhammad Mirza
for your comment. I don't care for perfectly transform limited pulse. I want to know, how can I compensate the chirp imposed by GVD, and what should be design parameters and considerations to design an efficient compressor, considering the amount of GVD my output pulse has undergone.
There are several techniques available, that I know of:
- prism compressors
- grating compressors
- compensating materials
Which all depend on the wavelength used.
Prism compressor (https://en.wikipedia.org/wiki/Prism_compressor):
Great thing: they are adjustable and have relatively low losses. You can build them yourself, for example with:
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=3242
or buy existing packages:
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=7733
Just look at different vendors for optics materials.
Grating compressor (https://en.wikipedia.org/wiki/Chirped_pulse_amplification):
Similar to the above. Might be more expensive and they have higher losses. Additionally to the mere path length you can also manipulate each wavelength individually, with a Spatial Light Modulator (SLM), after you split the wavelenghts up by the use of a Liquid crystal array. There you can tailor the delay for "each wavelength" individually, like explained here: Article Spatial light modulators
Compensating materials:
Materials with a negative Group Delay Dispersion. Either through a singular material, like Compensating Fibers, or structured materials, like dielectric mirrors with a tailored negative group delay dispersion. (Which is mentioned in the wikipedia Article about prism compressor). Problem here is, that they have a fixed GDD, that they can compensate.
I hope that helps you find a solution.
Best regards,
Christoph Dresler
There are several ways to compress the pulses. Common are Prism compressor, Grating compressor and Chirped mirrors.
It depends also on the pulse energy. For example if your pulse energy is in the range on mJ, you might not want to use Prism compressor as it is not suitable for higher energies due to nonlinear effects in the prism. Grating compressor avoids the nonlinearity problem, but it lacks throughput efficiency. In this case using Chirped mirrors is the best option as it gives high throughput and you can also control the amount of GDD by suitable number of reflections on the mirror.
Article Postcompression of picosecond pulses into the few-cycle regime
This article might be of help.
Cheers,
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