Best-in-Class Technologies
NRT's polarization controller offering is comprised of four key technologies:
- Integrated-optic Lithium Niobate (LiNbO3) waveguide polarization controller device. LiNbO3 polarization controllers are known for their super-fast electro-optic response which is useful for tracking polarization as well as polarization scrambling.
- Unique Control Algorithm running on a custom DSP and FPGA platform. The NRT Control Algorithm control enables:
- Virtually perfect SOP transformations with no dropouts or ‘glitches’
- Accurate and truly 'Endless' control of polarization
- Significant control improvement over other control algorithms
- 10x speed improvement over other control algorithms
- Leverages 4 years of PMD compensator control algorithm development
- Analog-to-digital converters for external electrical feedback signals
- The NRT-2500 is supported by a PC software package. Its open architecture allows you to optimize the performance for your application:
- Create your unique error signal from the A/D voltages (such as DOP from the S0, S1, S2, S3 of a polarimeter)
- Adjust algorithm parameters loop gain parameters.
- Run algorithm parameter optimization program
Why recreate the wheel?
Even so-called 'endless' polarization controllers are insufficient for mission critical applications without a robust tracking algorithm. Creating a dither-and-search feedback tracking algorithm is fairly straight forward, and a modestly performing algorithm can be written in relatively short order. However significant time, money manpower and knowledge are required to make an algorithm that is network deployable, capable of 'five-9s' reliability.
New Ridge has invested the time and effort, and has packaged it all together for you.
The NRT-2500 was derived from hardware and software developed originally for PMD compensation. This technology was qualified for network deployment at multiple carriers around the world proving its 'five-9s' robust network ready performance capabilities.
Sample Performance
Below is a set up for to test polarization tracking and to compare control algorithms. The goal for the control algorithm is to very quickly adjust the LiNbO3 polarization controller to minimize the light passing the polarizer and reaching the photodiode.
The results of this demonstration are shown below. The sophisticated algorithm offered by NRT (at the left) is clearly able to track the scrambled input the optical polarization maintaining a tighter locus circle of output polarizations than other common tracking algorithms (on the right).
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The output polarization states using the control algorithm in the NRT-2500: notice the clean and tight spot showing very fast and very accurate tracking, with no glitches.
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The output polarization states for a common polarization tracking algorithm: the diffuse spot shows instances where the algorithm lost track and could not keep up with the rotating input polarization.
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Applications |
controller designed for implementing very fast and very reliable polarization tracking applications such as:
