Optical Phase Locked Loop

[RAVIKUMAR K]

Dear All,

Has anyone used optiwave for simulation of optical phase locked loop? It would require a tuneable CW laser. Is it possible? Kindly suggest ways/methods to do so :-). THANKS.

[Hamza Ali Abbas Khan]

Hello Ravikumar
This has been mentioned in one thread under the name “feedback and individual samples”.
You may search it on the forum only. I will try to provide you with a link for the same.
Thanks

[Hamza Ali Abbas Khan]

Hello
This is the link https://optiwave.com/forums/topic/feedback-and-individual-samples-optical-system/

It has been rightly mentioned that in OptiSystem a signal is generally expressed as a sampled signal, which is passed to a component in one chunk. To perform time domain calculations, like feedback, the sampled signal must be converted to individual samples, which consist only of a single signal value and its corresponding position in time. This allows OptiSystem to propagate the samples through different components at different times. The attached project file Electric_Phase_Locked_Loop.osd is an example of an electrical feedback system.

You can follow the tutorial on this example at:

Electrical PLL

I hope this will be helpful to you.

Thanks
Regards

[RAVIKUMAR K]

Dear All,
Thanks for sharing this information. This is helpful to tackle feedback problem. Thanks a lot.
In case of optical Phase locked loop, I require Tunable laser (Local Oscillator) which is equivalent to VCO in electrical PLL.
Does anyone has reference on tunable laser (say tunable range of ~ 500 pm) in optiwave software?

Thanks !!!

[Karan Ahuja]

Hello.

As far as tunable lasers are concerned i want to mention that Tunable lasers have been the subject of considerable interest ever since the start of the wavelength division multiplexing (WDM) revolution. In this paper, we bring together views on tunable lasers from different types of companies in the value chain, from operators to laser manufacturers. The purpose is to give an overview of the state of the art in both deployment and development, as well as to try to predict trends over the coming years. A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. While all laser gain media allow small shifts in output wavelength, only a few types of lasers allow continuous tuning over a significant wavelength range.There are many types and categories of tunable lasers. They exist in the gas, liquid, and solid state. Among the types of tunable lasers are excimer lasers, gas lasers (such as CO2 and He-Ne lasers), dye lasers (liquid and solid state), transition metal solid-state lasers, semiconductor crystal and diode lasers, and free electron lasers. Tunable lasers find applications in spectroscopy,photochemistry, atomic vapor laser isotope separation, and optical communications.
I am providing link of a paper you may refer to it.
https://www.osapublishing.org/jlt/abstract.cfm?uri=jlt-24-1-5
The purpose of the paper is to give an overview of the state of the art in both deployment and development, as well as to try to predict trends over the coming years.

Thanks

[Karan Ahuja]

I also want to mention about Tunable semiconductor lasers. These have been listed in numerous critical technology lists for future optical communication and sensing systems. This paper summarizes a tutorial that was given at OFC ’03. It includes some discussion of why tunable lasers might be beneficial, an outline of basic tuning mechanisms, some examples of tunable lasers that have been commercialized, and a discussion of control techniques. More extensive data is given for the widely-tunable sampled-grating distributed-Bragg-reflector (SGDBR) type of laser, including data for such lasers integrated monolithically with modulators to form complete transmitter front ends. A summary of reliability data for the SGDBR laser is also given. It is concluded that tunable lasers can reduce operational costs, that full-band tunability is desirable for many applications, that monolithic integration offers the most potential for reducing size, weight, power and cost, and that sufficient reliability for system insertion has been demonstrated.
Here are few papers that may be of some help.
http://www.tunablelasers.com/tutorial.htm
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1589026&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1589026
http://ieeexplore.ieee.org/xpl/login.jsptp=&arnumber=1266694&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F50%2F28332%2F01266694.pdf%3Farnumber%3D1266694
https://www.google.co.in/urlsa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0ahUKEwi6zon8ycfNAhWMOY8KHdz3DZ8QFghJMAQ&url=http%3A%2F%2Fwww.ece.drexel.edu%2FCMLE%2Fpapers%2Frtmotlr%2Frtmotlr.doc&usg=AFQjCNGMRaSo_WbUfULscYRDfLhhHu58OA&bvm=bv.125596728,d.c2I

Thanks

[Aabid Baba]

Hello RaviKumar,
I would suggest you to go through the tutorial on this example as mentioned by Hamza Ali Abbas above .
Here is the link address.

Electrical PLL

You can also go through the thread posted by Damian about the implementation of phase locked loop in optisystem. It will be definitely very useful for your requirement. I hope this will be helpful to you. Thanking you.
Regards

[RAVIKUMAR K]

Dear Aabid Baba,

Thanks for your input. I have understood the implementation of phase locked loop for electrical systems. The point is here is PLL with optical system using optiwave. For this two things are required
1. Feedback environment in optiwave tool : This is now pretty clear for me, thanks to electrical pll link shared by you all.
2. Tunable laser simulation in optiwave: Optiwave library doesn’t have this component. Thus, this problem is still open. I am looking for – whether I can simulate tunable laser wherein electrical voltage will control the optical wavelength of laser source. Requesting help in this.

Dear Karan,
I understand advantages and implementation of tunable laser source. But problem here is simulation in optiwave. Optiwave doesn’t have the tunable laser component in library. I am looking at alternate ways to simulate this.

[Karan Ahuja]

Hi Ravikumar.

I think we can use tunable laser configuration in optisystem. here is a useful link to that

Erbium-doped Fiber Laser

Er-doped fiber lasers (EDFLs) can be viewed as EDFAs operating in the particular regime where coherent oscillation of ASE occurs due to some feedback means.A standard definition could be the following: EDFLs are used as sources for coherent light signal generation, while EDFAs are used as wave-wave amplifiers for coherent light signal regeneration.All EDFLs can be pumped with compact, efficient, and sometimes inexpensive laser diodes. They are compatible with different fibers and fiber optic components used in communications so they have negligible coupling losses.Fiber waveguiding and splicing alleviate any mechanical alignment of parts and provide superior environmental stability.
There are many possible laser cavity designs and configurations.The tunable EDFL configuration presented here uses an all-fiber ring laser cavity. Wavelength selectivity can be achieved by using a tunable transmission filter.This example will show how OptiSystem can simulate laser ring design and ASE sources.The setup parameters are very important to obtain a steady state output power. This means the user must find the minimum number of convergence iterations to obtain correct results.
You may refer to it. Hope it will help

Thanks

[Aabid Baba]

Hello RaviKumar,
As far as your query about availability of tunable lasers was concerned I think Karan has rightly mentioned the link here . You may refer to this link for further information. I hope this would help. Thanking you
Regards

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