Multi-Wavelength Light Emitter Layout for Compact Beam Combining
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Solution Overview
Problem
There is a need for miniaturizing light emitting devices while maintaining or improving their performance, particularly in reducing the size without compromising the efficiency of laser beam combining.
Innovation Solution
A light emitting device with three or more light emitting elements, each emitting light at different wavelengths, are disposed such that their optical axes form specific angles, allowing the light to converge and exit through a package with a light transmitting incident face, enabling efficient miniaturization by optimizing the layout and lens member design to reduce the overall package size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the intervals between laser beams from adjacent light emitting elements are reduced to decrease package size, then the package size is reduced, but the laser beam combining efficiency deteriorates due to interference between adjacent elements
Solution Approach 1:
The patent applies dimensional transformation by changing the spatial arrangement of light emitting elements from a linear one-dimensional layout to a two-dimensional angular configuration. Specifically, adjacent light emitting elements are disposed at angles of 3° to 45° relative to each other, causing their optical axes to diverge in different directions. This angular separation in a second dimension allows the laser beams to travel along separated optical paths, effectively preventing interference while maintaining a compact package footprint. The angled disposition transforms the problem from a one-dimensional spacing issue to a two-dimensional angular distribution problem, enabling miniaturization without sacrificing beam combining efficiency.
2Reliability
If the angle between optical axes of adjacent light emitting elements is increased to reduce interference, then the laser beam combining efficiency is improved, but the package size increases
Solution Approach 1:
The patent employs parameter optimization by establishing a specific angular range of 3° to 45° between the optical axes of adjacent light emitting elements. This parameter change balances two competing requirements: a small enough angle to maintain compact package dimensions, and a large enough angle to ensure sufficient optical path separation and prevent beam interference. The optimized angular parameter enables the system to achieve both miniaturization and high laser beam combining efficiency simultaneously, resolving the contradiction between package size and beam combining efficiency.
3Reliability
If the intervals between laser beams are gradually decreased towards the convergence lens to improve beam combining, then the laser beam combining efficiency is improved, but the initial package size becomes larger
Solution Approach 1:
The patent applies preliminary action by pre-establishing angular separation between the optical axes of adjacent light emitting elements at their source positions. This preliminary angular disposition ensures that laser beams are already separated along different optical paths before they travel toward the convergence lens, preventing interference from occurring in the first place. As a result, the beams can converge efficiently at the lens without requiring additional spacing or adjustment mechanisms along the optical path, thereby reducing the overall package length while maintaining high beam combining efficiency.
Data Source
AI summary
A light emitting device includes three or more light emitting elements, and a package that includes a base having a mounting face on which the three or more light emitting elements are disposed and a lateral wall part disposed around the light emitting elements and having a light transmitting incident face. The three or more light emitting elements include a first light emitting element that emits first light having an emission peak at a first wavelength along a first optical axis, a second light emitting element that emits second light having an emission peak at a second wavelength along a second optical axis, and a third light emitting element that emits third light having an emission peak at a third wavelength along a third optical axis. An angle formed by the first optical axis and the second optical axis in a top view is 3° to 45°. As the first light and the second light respectively travel along the first optical axis and the second optical axis, a first interval between the first optical axis and the second optical axis increases. The exiting first, second, and third lights are incident on the incident face.