Electron Beam Pumped VECSEL for UV Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor light emitting devices, particularly vertical external cavity surface emitting lasers (VECSELs), face limitations in emitting radiation at wavelengths below 400 nm due to the unavailability of compact optical pump sources, restricting their application in demanding spectral and spatial optical lasing characteristics.
Innovation Solution
The development of electron beam-pumped VECSELs with a heterostructure and distributed Bragg reflectors, where the active region is disposed between the reflectors to form an external cavity, allowing for longitudinal single-mode operation and direct emission of UV radiation between 200 nm and 400 nm, utilizing materials like InGaN for blue or green emission and AlGaN for UV emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If optical pump sources are used for VECSELs, then laser operation can be achieved, but compact optical pump sources are unavailable for wavelengths below 400 nm
Solution Approach 1:
The patent replaces the optical pump source (electromagnetic field-based pumping) with an electron beam pump source (particle-based pumping). This substitution enables UV wavelength generation below 400 nm where compact optical pump sources are unavailable, as the electron beam directly excites the active region without requiring optical pumping infrastructure.
2Adaptability or versatility
If electron beam pumping is implemented, then UV radiation emission below 400 nm is achieved, but device complexity increases
Solution Approach 1:
The patent merges the electron beam pump source with the VECSEL structure by integrating the pump source within the same device housing or mounting arrangement. This combination consolidates multiple components (electron beam source, heterostructure, reflectors) into a unified system, reducing overall device complexity despite the advanced pumping mechanism.
3Length of moving object
If the heterostructure is disposed close to the first reflector, then device compactness is improved, but the external cavity length is reduced
Solution Approach 1:
The patent positions the heterostructure laterally offset from the optical axis rather than directly adjacent to the first reflector along the optical path. This lateral displacement in a different spatial dimension allows the device to maintain compact overall length while preserving sufficient external cavity length along the optical axis for proper laser operation.
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 configuration enables high-power, compact, and lightweight VECSEL systems with improved spectral and spatial lasing characteristics, suitable for applications like Raman Spectroscopy, achieving high beam quality and output power in the UV range.
Implementation Method 1
an active region that includes one or more quantum well structures configured to emit radiation at a wavelength, λlase, in response to pumping by an electron beam
Implementation Method 2
quantum well structures configured to emit radiation at a wavelength, λlase
Implementation Method 3
first and second reflectors... The heterostructure is disposed between the first reflector and the second reflector
Data Source
AI summary
A vertical external cavity surface emitting laser (VECSEL) structure includes a heterostructure and first and second reflectors. The heterostructure comprises an active region having one or more quantum well structures configured to emit radiation at a wavelength, λlase, in response to pumping by an electron beam. One or more layers of the heterostructure may be doped. The active region is disposed between the first reflector and the second reflector and is spaced apart from the first reflector by an external cavity. An electron beam source is configured to generate the electron beam directed toward the active region. At least one electrical contact is electrically coupled to the heterostructure and is configured to provide a current path between the heterostructure and ground.