Intracavity Tap Outcoupling for Laser Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser modules, particularly those using Fabry-Pérot (FP) and distributed Bragg reflector (DBR) lasers, face high production costs and optical losses due to the need for external components like beam-splitters, etalons, and variable optical attenuators, and struggle with efficient coupling of laser light from the facet to a second chip, leading to reduced output power and complex integration processes.
Innovation Solution
The implementation of an intracavity tap outcoupling scheme in FP or DBR lasers, where a tap section is placed within the cavity between reflectors to extract a portion of the laser beam, allowing for reduced external components and improved output power performance by directing the light into a waveguide, thereby integrating additional functionalities and enhancing module performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external bulk optical components (beam-splitters, etalons, VOAs) are used to provide laser module functionalities, then the module can achieve required performance, but the production cost increases significantly (more than 80% of total production cost) and additional optical loss occurs reducing output power
Solution Approach 1:
The patent merges the laser cavity with additional functional units (power monitor, wavelength locker, VOA) into a single integrated structure. The waveguide-based devices are monolithically integrated with the laser, eliminating the need for separate external bulk optical components and reducing both complexity and cost while maintaining required performance
Solution Approach 2:
The patent implements multi-functionality by integrating multiple functional units (power monitoring, wavelength locking, attenuation control) within the same laser module structure. These functions are achieved through waveguide-based devices that can be monolithically integrated, allowing one system to perform multiple roles that previously required separate external components
2Ease of manufacture
If a lens is used to couple laser light from the facet to a second chip, then integration with functional units is achieved, but coupling loss increases and high-precision mounting is required
Solution Approach 1:
The patent extracts the light coupling function from the external lens-based system and integrates it directly into the laser chip structure. The waveguide-based functional units are monolithically integrated with the laser, eliminating the need for separate lens coupling and reducing coupling loss while simplifying the manufacturing process
Solution Approach 2:
The patent introduces waveguide-based structures as intermediaries between the laser facet and functional units. These waveguides provide efficient light transmission paths with low loss, replacing the lens-based coupling system and enabling direct integration without high-precision mounting requirements
3Ease of manufacture
If DBR laser with diffraction grating is used for integration, then direct coupling to waveguide is possible, but output power is significantly reduced due to lossy diffraction grating
Solution Approach 1:
The patent changes the grating parameters (depth, width, spacing) to optimize the balance between diffraction efficiency and output power. By carefully controlling these geometric parameters, the system achieves effective wavelength selection through the diffraction grating while minimizing power loss and maintaining high output power
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 reduces the number of optical components, enhances output power performance, and allows for more compact, reliable, and cost-effective laser modules by directing a large fraction of the laser light into a waveguide, offering superior power handling and integration capabilities compared to conventional front facet outcoupling schemes.
Implementation Method 1
a tap section provided in the cavity to take out a part of the laser beam
Data Source
AI summary
A laser source includes a laser beam generating section for generating a laser beam in a cavity between first reflector and a second reflector; and a tap section provided in the cavity to take out a part of the laser beam. The laser source is a waveguide-based laser source.