Tunable Laser With Single Microring Resonator and SOA
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Solution Overview
Problem
Existing tunable lasers face challenges in wavelength calibration and control due to thermal sensitivity of silicon waveguides, leading to difficult vernier tuning and high manufacturing process requirements.
Innovation Solution
A tunable laser design incorporating a reflective semiconductor optical amplifier, grating codirectional coupler, and reflective microring resonator, with a narrow-band pass filter and comb-shaped filtering spectrum, allowing for easier wavelength tuning by aligning only one center wavelength, reducing the need for precise alignment of multiple center wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a vernier tuning mechanism with two wavelength-adjustable filters is used to implement broadband wavelength tuning, then the wavelength tuning range is improved, but the device complexity and manufacturing precision requirements increase
Solution Approach 1:
The patent extracts one of the two filters from the vernier tuning mechanism, retaining only a single microring resonator. This simplifies the structure while maintaining the ability to achieve broadband tuning through alternative means (electric field effect on the SOA), thereby reducing device complexity while preserving adaptability.
Solution Approach 2:
The semiconductor optical amplifier (SOA) is designed to serve multiple functions: it provides optical gain for laser operation and simultaneously acts as a wavelength tuning element through electric field effect. This multi-functionality eliminates the need for separate tuning filters, reducing overall device complexity while maintaining broad wavelength tuning capability.
2Adaptability or versatility
If a vernier tuning mechanism with two microring resonators is used, then wavelength tuning capability is improved, but the ease of operation deteriorates due to difficult wavelength calibration
Solution Approach 1:
The patent removes one microring resonator from the vernier tuning mechanism, leaving a single resonator. This eliminates the complex interaction between two resonators that makes calibration difficult, while the SOA's electric field tuning capability compensates by enabling straightforward wavelength adjustment without requiring precise dual-resonator alignment.
3Ease of manufacture
If silicon waveguide is used in the vernier tuning mechanism, then the manufacturing process is simplified, but the reliability deteriorates due to thermal sensitivity causing filtering spectrum drift
Solution Approach 1:
The patent replaces thermal tuning mechanisms with electric field tuning via the SOA. This substitution eliminates thermal effects that cause spectrum drift in silicon waveguides, improving wavelength stability and reliability while maintaining the benefits of silicon-based fabrication.
Solution Approach 2:
The patent changes the tuning mechanism from thermal parameter changes (temperature-dependent refractive index) to electric field parameter changes (carrier concentration-dependent refractive index in SOA). This parameter change eliminates thermal sensitivity issues while enabling reliable wavelength tuning in silicon waveguide structures.
4Adaptability or versatility
If vernier tuning mechanism is used for wavelength tuning, then the wavelength tuning range is improved, but the productivity deteriorates due to slow tuning speed
Solution Approach 1:
The patent replaces the mechanical/thermal tuning mechanism with electric field tuning through the SOA. Electric field effects occur almost instantaneously compared to thermal processes, enabling fast wavelength switching while maintaining broad tuning range, thus improving productivity without sacrificing adaptability.
Solution Approach 2:
The patent transitions from slow thermal parameter changes to fast electric field parameter changes for wavelength tuning. This parameter change enables rapid wavelength switching speeds suitable for high-speed optical communication applications while preserving the broad wavelength tuning capability.
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 design simplifies wavelength tuning, increases tuning speed, and reduces the complexity and cost of the wavelength test process, while maintaining accurate wavelength control.
Implementation Method 1
a first grating is disposed on the first waveguide, a second grating disposed opposite to the first grating is disposed on the second waveguide, and the first grating and the second grating constitute a narrow-band pass filter
Implementation Method 2
the reflective microring resonator has a comb-shaped filtering spectrum
Implementation Method 3
The SOA 11 provides an optical gain
Implementation Method 4
an anti-reflection film is disposed on a first end surface of the reflective SOA
Data Source
AI summary
A tunable laser includes a reflective semiconductor optical amplifier (SOA), a grating codirectional coupler, and a reflective microring resonator. The grating codirectional coupler and the reflective microring resonator are both formed on a silicon base. An anti-reflection film is disposed on a first end surface of the reflective SOA, and the first end surface is an end surface, coupled to a first waveguide of the grating codirectional coupler, of the reflective SOA. A second waveguide of the grating codirectional coupler is coupled to the first waveguide, a first grating is disposed on the first waveguide, a second grating disposed opposite to the first grating is disposed on the second waveguide, and the first grating and the second grating constitute a narrow-band pass filter. The second waveguide is connected to the reflective microring resonator.