Vertical Cavity Light Emitting Sources Using Patterned Membrane Reflectors
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Solution Overview
Problem
The integration of photonic components with electronic components on silicon substrates is hindered by the lack of a practical, efficient, ultra-compact, electrically controllable, and reliable silicon-integrated light source, with conventional vertical-cavity light emitting sources being limited by thick distributed-Bragg reflector mirrors.
Innovation Solution
The development of vertical cavity light emitting sources using stacked semiconductor membranes with patterned membranes as reflectors, which eliminate the need for DBRs, allowing for compact, efficient, and electrically controllable light sources that can be fabricated directly on silicon wafers, enabling high-density integration and emission across various wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional vertical-cavity light emitting sources use thick distributed-Bragg reflector (DBR) mirrors, then the device structure is stable and functional, but the device size increases and integration density decreases
Solution Approach 1:
The patent replaces conventional thick DBR mirrors with thin film reflectors having reflectivity greater than 0.99. These thin film reflectors achieve the necessary optical feedback while dramatically reducing the vertical cavity thickness, enabling compact light sources suitable for high-density integration on silicon substrates without sacrificing device stability or functionality
Solution Approach 2:
The patent changes the optical parameters of the reflector by using materials and structures with high reflectivity in the thin film regime. This allows the cavity to maintain proper optical feedback conditions with significantly reduced thickness compared to conventional DBR-based designs, resolving the contradiction between stability and compactness
2Reliability
If vertical cavity light emitting sources are fabricated with thick DBR mirrors, then the optical feedback is sufficient, but the fabrication complexity and manufacturing difficulty increase
Solution Approach 1:
The thin film reflectors simplify the fabrication process by eliminating the need to grow or deposit thick DBR mirror structures. The thin film approach is more compatible with standard semiconductor manufacturing processes and allows for easier integration with silicon-based photonic circuits, reducing overall fabrication complexity while maintaining sufficient optical feedback
Solution Approach 2:
The patent extracts and eliminates the thick DBR mirror component from the conventional VCSEL structure, replacing it with thin film reflectors. This removal of the bulky DBR layer simplifies the manufacturing process and reduces the number of fabrication steps required while preserving the essential optical feedback function
3Reliability
If conventional VCSELs use thick DBR mirrors, then the device is functional, but the integration density with silicon photonics decreases
Solution Approach 1:
The thin film reflectors enable high-density integration by reducing the vertical space required for each light source device. This allows multiple VCSELs to be packed more closely together on silicon substrates, increasing the productivity and scale of silicon-based photonic systems while maintaining full device functionality
Solution Approach 2:
By transitioning from thick vertical structures to thin film-based reflectors, the patent effectively shifts the design paradigm to allow for higher lateral integration densities. The reduced vertical footprint enables more devices to be integrated on the same silicon substrate area, enhancing overall system productivity
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 approach enables the creation of compact, efficient, and reliable vertical cavity light emitting sources that can be integrated on silicon substrates, facilitating high-density photonics integration while allowing for tailored emission across a broad spectrum, including ultraviolet, visible, and infrared regions, and enabling efficient electrical injection.
Implementation Method 1
The patterned membrane reflectors can be structures based on Fano resonance or guided resonance effect, where in-plane guided resonances above the lightline are also strongly coupled to out-of-the-plane radiation modes due to phase matching provided by the patterned lattice structure
Implementation Method 2
The patterned membrane reflectors can be structures based on Fano resonance or guided resonance effect, where in-plane guided resonances above the lightline are also strongly coupled to out-of-the-plane radiation modes due to phase matching provided by the patterned lattice structure
Data Source
AI summary
Vertical cavity light emitting sources that utilize patterned membranes as reflectors are provided. The vertical cavity light emitting sources have a stacked structure that includes an active region disposed between an upper reflector and a lower reflector. The active region, upper reflector and lower reflector can be fabricated from single or multi-layered thin films of solid states materials (“membranes”) that can be separately processed and then stacked to form a vertical cavity light emitting source.