Quantum Cascade Laser CeO2 Reflectance Control
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Solution Overview
Problem
There is a lack of materials that effectively provide reflectance control for mid-infrared light in quantum cascade lasers, particularly for wavelengths between 7 to 15 μm, while also ensuring good insulation properties on device end faces.
Innovation Solution
A quantum cascade laser is designed with a reflection control film incorporating at least one layer of CeO2, which exhibits high transparency and insulation properties in the mid-infrared region, applied to the end faces of the laser cavity structure to achieve reflectance control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional materials are used for reflection control films on quantum cascade laser end faces, then the device structure can be formed, but the materials fail to provide sufficient reflectance control for mid-infrared light in the 7 to 15 μm wavelength region
Solution Approach 1:
The patent changes the material parameter from conventional dielectric materials to cerium oxide (CeO2), which has unique optical properties in the mid-infrared region. This material substitution enables effective reflectance control for wavelengths of 7 to 15 μm while maintaining good insulation properties on the laser device end face.
Solution Approach 2:
The patent employs a composite film structure consisting of multiple layers including CeO2 layers combined with other dielectric materials. This composite approach allows optimization of both optical performance (reflectance control) and electrical properties (insulation) by combining the advantages of different materials in a multi-layer configuration.
2Use of energy by moving object
If existing materials are used for mid-infrared reflectance control, then the device can operate, but light permeability and insulation are not optimized
Solution Approach 1:
The patent optimizes the optical parameter of light permeability by selecting CeO2, which has high transparency in the mid-infrared region. Simultaneously, the material maintains good insulation properties, resolving the trade-off between optical performance and electrical insulation.
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 use of CeO2 films enables effective reflectance control for mid-infrared light, improving the performance and stability of quantum cascade lasers by enhancing light permeability and insulation, thus addressing the limitations of existing materials.
Implementation Method 1
a reflection control film including at least one layer of CeO2 film is formed on at least one of a first end face and a second end face
Implementation Method 2
CeO2 (cerium oxide) is a material showing high permeability to light within a mid-infrared region
Implementation Method 3
the active layer generates light by intersubband transition in a quantum well structure
Data Source
AI summary
A quantum cascade laser includes a semiconductor substrate, and an active layer that is provided on the substrate, and has a cascade structure in which emission layers and injection layers are alternately laminated by multistage-laminating unit laminate structures each consisting of the quantum well emission layer and the injection layer, the active layer generates light by intersubband transition in a quantum well structure. Further, in a laser cavity structure for light with a predetermined wavelength to be generated in the active layer, reflection control films including at least one layer of CeO2 film are formed on a first end face and a second end face facing each other. Thereby, it is possible to realize a quantum cascade laser capable of preferably realizing reflectance control for light within a mid-infrared wavelength region on the laser device end face.