Semiconductor Laser Source with Temperature-Insensitive Filter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor laser sources are sensitive to temperature variations, causing their emission wavelength to drift, and require bulky and power-consuming temperature regulation devices to maintain stability.
Innovation Solution
A semiconductor laser source with a filter made from a material less sensitive to temperature, integrated into a three-waveguide structure using silicon, III-V gain material, and a material with reduced refractive index variation, along with a tuning device and sensor to center the wavelength at the filter's passband, reducing temperature-induced wavelength drift without external temperature regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a filter made of silicon is used in the laser source, then the manufacturing is simplified and integration is easier, but the emission wavelength becomes highly sensitive to temperature variations
Solution Approach 1:
The patent uses a composite material structure where the filter is made of a material with low refractive index temperature dependence (such as silicon nitride or silicon oxide) while other components remain in silicon. This composite approach allows the filter to be less sensitive to temperature variations while maintaining ease of manufacture through standard semiconductor processing techniques for multiple material layers.
2Reliability
If temperature regulation devices are added to the laser source, then the emission wavelength stability is improved, but the device becomes bulkier and consumes more power
Solution Approach 1:
The patent makes the filter itself temperature-compensating by using a material whose refractive index varies less with temperature. The filter automatically compensates for temperature-induced wavelength drift without requiring external regulation devices, thereby maintaining wavelength stability while avoiding increased device complexity and power consumption.
Solution Approach 2:
The patent changes the material parameter (refractive index temperature dependence) of the filter from silicon to a material with lower temperature dependence. This parameter change in the filter material inherently reduces the laser source's sensitivity to temperature variations, eliminating the need for bulky and power-consuming temperature regulation devices while maintaining emission wavelength stability.
3Object-affected harmful factors
If a material with low refractive index temperature dependence is used for the filter, then the temperature drift is reduced, but the manufacturing complexity increases
Solution Approach 1:
The patent employs composite material structures combining silicon with materials like silicon nitride or silicon oxide for the filter. These composite structures can be manufactured using established semiconductor processing techniques including sequential deposition and selective etching, thereby reducing manufacturing complexity despite using multiple materials.
Solution Approach 2:
The patent uses silicon oxide or silicon nitride as intermediary materials between the silicon waveguide and the filter structure. These intermediary layers facilitate the integration of low temperature-dependence materials into the existing silicon photonics platform, simplifying the manufacturing process while achieving reduced temperature drift.
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
The solution significantly reduces the sensitivity of the laser source to temperature changes, allowing for a more compact and power-efficient design while maintaining precise wavelength control.
Implementation Method 1
a passband filter produced in a waveguide and arranged to be passed through by the optical signal resonating between the front and back reflectors, this passband filter being able to select at least one wavelength λLi from the wavelengths λRj
Implementation Method 2
this waveguide being coupled to the waveguide made of silicon by adiabatic coupling that is able to convert a guided optical mode of the waveguide made of silicon into a guided optical mode of the waveguide made of III-V gain material
Implementation Method 3
a front reflector and a back reflector, these front and back reflectors forming the ends of a Fabry-Pérot optical cavity able to make resonate an optical signal at a plurality of possible resonant frequencies
Data Source
AI summary
A semiconductor laser source wherein a waveguide in which a filter is produced is made of a material that is less sensitive to temperature. The laser source also includes a tuning device able to shift the possible resonant wavelengths ΔλRj of a Fabry-Pérot optical cavity in response to an electrical controlling signal, a sensor able to measure a physical quantity representative of the difference between a central wavelength λCf of the filter and one of the possible wavelengths λRj, and an electronic circuit able to generate, depending on the physical quantity measured by the sensor, the electrical signal controlling the tuning device in order to keep one wavelength λRj at the center of each passband of the filter that selects an emission wavelength λLi of the laser source.