Optical Fiber End Cap Design for Laser Oscillator Moisture Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical fiber laser oscillators face challenges in preventing damage from moisture deliquescence and heat generation, particularly when the optical fiber ends are exposed or inadequately cooled between metallic plates.
Innovation Solution
The optical fiber design includes a first optical fiber body with a higher laser medium doping and a second optical fiber body with lower doping, both joined with end caps to prevent exposure and heat absorption, allowing for effective cooling and protection from moisture and heat damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the optical fiber ends are exposed to the atmosphere, then the laser light can be output, but the end surfaces deliquesce by moisture absorption
Solution Approach 1:
An end cap made of calcium fluoride is introduced as an intermediary component between the optical fiber end surface and the atmosphere. This end cap prevents moisture from contacting the fluoride glass end surface, thereby preventing deliquescence while still allowing laser light to pass through due to calcium fluoride's high light permeability in the laser wavelength range.
2Temperature
If the optical fiber is interposed between metallic plates for cooling, then heat damage is prevented, but the fiber ends may still be exposed and damaged
Solution Approach 1:
The end cap serves as a mediator that provides both atmospheric sealing and thermal conduction. It is in contact with both the optical fiber end surface and the metallic cooling plate, transferring heat from the fiber to the plate while preventing moisture ingress, thus simultaneously addressing both cooling and protection requirements.
3Power
If the laser medium doping is increased to improve laser output, then heat generation increases and causes damage
Solution Approach 1:
The doping concentration of the laser medium (erbium) is optimized to balance laser output power and heat generation. By carefully controlling the erbium doping level, the patent achieves sufficient laser output while minimizing excessive heat generation that would cause fiber damage.
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 effectively inhibits damage to the optical fiber ends by preventing deliquescence and heat-related issues, ensuring stable operation of the laser oscillator.
Implementation Method 1
fluoride glass such as ZBLAN glass deliquesces by moisture contained in the atmosphere
Implementation Method 2
the optical fiber is interposed and held between two metallic plates and heat from the optical fiber is transferred thereto
Implementation Method 3
The laser medium contained in the optical fiber generates heat by absorbing the excitation light
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An optical fiber (6) includes a first optical fiber body (61), a second optical fiber body (62) and a first end cap (63). The first optical fiber body (61) includes a first core (611) and a first cladding (612) . The second optical fiber body (62) includes a second core (621) and a second cladding (622), and is joined at a first end surface (623) thereof to a first end surface (613) of the first optical fiber body (61). The first end cap (63) has light permeability and is joined to a second end surface (624) of the second optical fiber body (62). The first core (611) is doped with a laser medium. A mass content of the laser medium in the second core (621) is lower than that of the laser medium in the first core (611).