Flexible Membrane Laser with DFB Gratings for Optical Identification
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Solution Overview
Problem
Membrane lasers based on organic semiconductors are difficult to fabricate and fragile, limiting their applications due to mechanical inflexibility and susceptibility, despite their potential for low-cost, lightweight, and flexible devices.
Innovation Solution
A membrane laser structure with a flexible emission layer and grating structures providing distributed optical feedback, allowing for optically pumped laser light output with unique properties that can serve as identifiers, attached to various objects for security, identification, or sensing purposes, utilizing a water-soluble sacrificial layer for mechanical flexibility and transferability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If membrane lasers are made with organic semiconductors to achieve low-cost and lightweight devices, then the device weight and cost are reduced, but the mechanical flexibility and fragility are worsened
Solution Approach 1:
The patent employs thin film structures throughout the laser device, including the organic semiconductor gain medium layer (5-50 nm), distributed feedback grating layer (30-120 nm), and encapsulation layers. These thin film configurations enable the laser to achieve mechanical flexibility while maintaining functional performance, directly resolving the contradiction between weight reduction and mechanical reliability
Solution Approach 2:
The patent utilizes composite material structures combining organic semiconductors with flexible substrate materials and encapsulation layers. The multi-layer composite structure integrates the optical properties of organic semiconductors with the mechanical flexibility of polymer substrates, achieving both low weight and improved mechanical reliability simultaneously
2Power
If the gain material thickness is increased to at least 10 nm to improve laser output, then the laser performance is enhanced, but the device complexity and fabrication difficulty increase
Solution Approach 1:
The patent optimizes the gain material thickness parameter to a specific range (5-50 nm) that balances laser output performance with fabrication feasibility. This parameter optimization allows sufficient optical gain while maintaining compatibility with standard thin film deposition techniques, resolving the contradiction between power output and fabrication complexity
Solution Approach 2:
The patent replaces traditional mechanical laser cavity structures with a distributed feedback (DFB) grating system implemented through nanoscale periodic structures in the thin film. This substitution eliminates complex mechanical alignment requirements while achieving stable laser output, reducing fabrication difficulty despite the need for precise thickness control
3Measurement precision
If grating structures with groove depth of 30nm to 120nm are formed to provide distributed optical feedback, then the laser wavelength precision is improved, but the manufacturing precision requirements are worsened
Solution Approach 1:
The patent introduces a distributed feedback grating structure as an intermediary element that converts nanoscale groove depth variations (30-120 nm) into precise wavelength selection. The grating acts as a mediator that transforms manufacturing tolerances in groove depth into controlled wavelength output, achieving wavelength precision while relaxing strict groove depth control requirements
Solution Approach 2:
The patent employs groove depths in the range of 30-120 nm, which provides sufficient optical feedback for wavelength precision without requiring extremely precise control at the lower end of this range. This partial action approach allows manufacturing processes to operate within a broader tolerance window while still achieving the desired laser wavelength precision
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
The membrane laser structure achieves mechanical flexibility, low weight, and a unique lasing spectrum suitable for security features, authentication, and sensing, with a lasing threshold below human eye safety limits, enabling applications such as wearable security tags and counterfeit prevention.
Implementation Method 1
one or more structures formed in or associated with the flexible emission layer, wherein the one or more structures comprise one or more gratings comprising a groove depth of 30nm to 120nm and are configured to provide distributed optical feedback in the emission layer to produce a laser light output
Implementation Method 2
the one or more structures comprise one or more gratings comprising a groove depth of 30nm to 120nm
Implementation Method 3
a membrane laser structure configured to be optically pumped
Implementation Method 4
produce a laser light output having at least one property representing an identifier
Data Source
Figure 1~2
Figure 3a~3f
Figure 3g
AI summary
A security or identification device comprises a membrane laser structure configured to be optically pumped. The membrane laser structure comprises a flexible emission layer comprising a gain material; and one or more structures formed in or associated with the flexible emission layer and configured to provide optical feedback in the emission layer to produce a laser light output having at least one property representing an identifier.