Is there a laser element where I can describe its behaviour using experimental data?

laser
interconnect

#1

Say I’ve got a commercially available laser and its data sheet. Some key specs are:

  • Peak emission wavelength
  • Threshold current
  • Slope efficiency
  • Small signal bandwidth

In INTERCONNECT, how can I describe such a laser?


#2

Hi @xwang,

Yes, you can customize your own laser model by using some primitive elements if you have the key specs of the design you want. In the attached example laser_example.icp (241.7 KB), the compound laser model is based on a primitive CW Laser and the LI information LI.txt (1.4 KB) is loaded into the Optical Modulator Measured element to tune the CW Laser. This model can be used as a start point for your design, If you can combine the threshold current and slope efficiency into this LI curve, you can directly load it into this model.

For the small signal modulation, the continuous wave laser cannot really model this effect. But you can replace it with the Directly Modulated Laser model to include the rate equation information.

I hope this could help :slight_smile:


#3

Hi @xwang,

We added two new elements in INTERCONNECT, namely Optical Modulator Lookup Table (OM) and Lookup Table (TABLE). The Optical Modulator Lookup Table can replace the Optical Modulator Measured element in the previously attached example file and still make the laser model. Please check out the new example file that contains both of the configurations laser_example_new.icp (421.4 KB). The LI data file is the same LI.txt (1.4 KB)

I hope this could help :slight_smile:


#5

Hi @gwang,

Can I use the “Traveling Wave Laser Model” of Lumerical Interconnect to simulate the linewidth and SMSR of a FP lasers?
Assuming that we have the experimental data of the SOA device, how can we modify the parameters of TWLM?


#6

Hi @ljliang,

Yes, you can use the TWLM model to simulate the laser linewidth and side-band suppression. For some of the examples, please refer to the KB pages Fabry-Perot Laser and DBR Laser.

What experimental data do you have exactly? I think some of them may be able to directly type/implement in to the model while some of them may need some post processings. Please let me know what you have and we can move on from there.

I hope this could be helpful :slight_smile:


#7

Thank you for your response @gwang

I think we can only get some SOA Gain data, that is, gain curves. So how to fitting the “gain parameters” in Interconnect TWLM with the experimental data?
What is more, we do not know the accurate “carrier recombination” and “Spontaneous Emission” coefficients for a SOA, too many parameters in TWLM are to be set.
That is the reason why I am wondering whether we can get some relative accurate numerical simulation predictions for a lasers.


#8

Hi @ljliang,

Sorry for this super late reply… hopefully the answer is still meaningful. We are enhancing the the new gain curve fitting for this TW laser model and the more advanced model that allows gain curve fitting will be available soon. I will definitely keep you in the loop about this and for now, you cannot fit the gain curves. Now the model uses a Lorentzian gain curve shape and you can only define the gain center, gain quality factor and gain compression factor.

For the reasonable values of the “carrier recombination” and “spontaneous emission”, I think the first question is, what do you want to use this model for, a laser or an amplifier (SOA)? If you already have a working laser, these values can be roughly calculated from the carrier decay and modulation response and so on. Otherwise, you may have to do trail and error fit and guess for the values.

I hope this could help :slight_smile: I would like to know more about your applications of this model and I will let you know when the new advanced model is ready.


#9

Hi @ljliang and @xwang,

The gain curve fitting feature is now available in the TWLM laser model in INTERCONNECT! Please find more information on this through the following link and example:

Gain fitting: https://kb.lumerical.com/en/index.html?laser_gain-fitting.html

I am sure this will make your design easier and handy. I’d love to discuss more on this if you have further inquires :slight_smile: