Photonic Integrated Circuit Optical Phased Array Calibration via UV Laser Trimming
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Solution Overview
Problem
Next-generation optical phased arrays face challenges due to manufacturing tolerances, which result in slight differences in center wavelengths of phase modulators, requiring calibration and increased electrical power consumption to compensate for these offsets.
Innovation Solution
A system and method for parallel real-time photonic integrated circuit (PIC) optical phased array calibration using ultraviolet laser micro-ring wavelength offset trimming, where ultraviolet illumination is applied to modify the index of refraction of phase modulators, allowing for precise tuning of center wavelengths and reducing the need for active compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If active compensation is used to correct wavelength offsets, then manufacturing tolerance variations can be compensated, but electrical power consumption increases
Solution Approach 1:
The patent replaces the active electrical compensation mechanism with a passive optical process. Instead of using electrical signals to adjust the wavelength offsets dynamically, the invention uses ultraviolet laser illumination to induce permanent refractive index changes in the waveguide material, thereby passively correcting the wavelength offsets without requiring continuous electrical power consumption.
Solution Approach 2:
The patent changes the physical state of the waveguide material by using ultraviolet laser illumination to induce permanent refractive index changes. This parameter change allows the waveguide to passively compensate for wavelength offsets by modifying its optical properties permanently, eliminating the need for continuous active electrical compensation.
2Manufacturing precision
If active compensation circuits are implemented, then wavelength calibration can be achieved, but circuit complexity increases
Solution Approach 1:
The patent replaces complex active compensation circuits with a simple passive optical process. Instead of implementing intricate electrical control circuits to dynamically adjust wavelengths, the invention uses ultraviolet laser illumination to induce permanent refractive index changes, thereby simplifying the system from active circuit-based control to passive optical correction.
Solution Approach 2:
The patent extracts the wavelength calibration function from the active circuit domain and implements it in the passive optical domain. By using ultraviolet laser-induced refractive index changes, the calibration process is removed from the circuit-based active compensation system, thereby reducing circuit complexity while maintaining calibration precision.
3Measurement precision
If ultraviolet illumination is applied to modify refractive index, then center wavelengths can be precisely tuned, but the process requires real-time monitoring and control
Solution Approach 1:
The patent implements feedback by monitoring the center wavelength shifts during and after ultraviolet illumination. The system measures the actual wavelength changes and uses this information to adjust the illumination parameters or compensate for any residual offsets, thereby achieving precise wavelength tuning while maintaining control through feedback mechanisms.
Solution Approach 2:
The patent applies preliminary action by using ultraviolet laser illumination to pre-adjust the refractive index of the waveguide material before final wavelength calibration is completed. This preliminary refractive index modification enables subsequent precise wavelength tuning with reduced complexity, as the bulk of the correction is performed passively in advance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables precise tuning of phase modulators, reducing power consumption and simplifying control schemes by replacing active compensation with passive techniques, thereby reducing electrical power draw and circuit complexity.
Implementation Method 1
directing ultraviolet illumination onto at least a subset of the unit cells simultaneously in order to change the center wavelengths of at least a subset of the modulators
Data Source
AI summary
A method includes obtaining a photonic integrated circuit having an optical phased array. The optical phased array includes multiple unit cells, and each unit cell includes (i) an antenna element configured to transmit or receive optical signals and (ii) a modulator configured to modify phases of the optical signals. The method also includes identifying center wavelengths of the modulators in the optical phased array. The method further includes directing ultraviolet illumination onto at least a subset of the unit cells simultaneously in order to change the center wavelengths of at least a subset of the modulators in the optical phased array. In addition, the method includes monitoring changes to the center wavelengths of at least the subset of the modulators in the optical phased array.