Semiconductor Laser Electrode Segmentation for COD Prevention
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Solution Overview
Problem
Semiconductor laser devices face issues with catastrophic optical damage (COD) and rapid degradation of light output due to excessive current application, where simply arranging ohmic electrodes with lengths less than the resonator length can prevent COD but lead to reduced light output.
Innovation Solution
The semiconductor laser device design includes a semiconductor laser element with a support member, where the second electrode is spaced apart from the emitting facet, and a pad electrode is positioned to extend beyond the second electrode's end portion, improving heat dissipation and preventing both COD and rapid degradation of light output by ensuring efficient current distribution and heat management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the ohmic electrode length is reduced to prevent COD, then COD is prevented, but light output rapidly degrades
Solution Approach 1:
The electrode structure is segmented into multiple functional regions: the first electrode (emitting side electrode) with length less than the resonator to prevent COD, and the second electrode (pad electrode) extending beyond the first electrode to maintain light output. This segmentation allows different parts of the electrode structure to fulfill different functions - the first electrode region controls current distribution to prevent damage, while the second electrode region ensures sufficient current supply for high light output.
2Illumination intensity
If high current is applied to increase light output, then light output increases, but COD occurs due to excessive light output
Solution Approach 1:
Different regions of the electrode structure are assigned different properties: the first electrode region has a length specifically controlled to be less than the resonator length to create a current-free zone at the emitting end surface, preventing local overheating and COD. Meanwhile, the second electrode extends beyond the first electrode to provide sufficient current supply to the active layer, ensuring high light output capability without causing damage at the critical emitting surface.
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 prevents catastrophic optical damage and rapid degradation of light output by maintaining high light output levels, as evidenced by I-L measurement results showing extended current tolerance without damage to the end surfaces.
Implementation Method 1
a pad electrode, and a support member. The second electrode is spaced apart from the emitting facet... the pad electrode is positioned to extend beyond the second electrode's end portion
Implementation Method 2
an active layer... a semiconductor laser element in which an 'ohmic electrode' for supplying electric current to the active layer
Implementation Method 3
improving heat dissipation and preventing both COD and rapid degradation of light output by ensuring efficient current distribution and heat management
Data Source
Figure 1
Figure 2(a)~2(c)
Figure 3~4
AI summary
The present invention is aimed to prevent occurrence of COD and rapid degradation of light output in semiconductor laser devices. The semiconductor laser device includes a semiconductor laser element 100A and a support member 200. The semiconductor laser element 100a includes a first electrode 13, a substrate 11, and a semiconductor structure 12 having an emitting facet and a reflecting facet, a second electrode 15, and a pad 16, in this order. The semiconductor laser element 100A is connected to a support member 200 at its pad 16 side via a connecting member 300. The emitting-side end portion of the second electrode 15 is spaced apart from the emitting facet of the semiconductor structure 12, and the emitting-side end portion of the pad 16 is located at an outer side than the emitting-side end portion the second electrode 15.