Optical Detector Using Spin Seebeck Effect for Broadband Light Detection
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Solution Overview
Problem
Current optoelectronic devices face challenges in incorporating spin functionality into traditional architectures and detecting broadband light effectively, with limited methods for measuring spin current density and inefficient light detection across a wide wavelength range.
Innovation Solution
The implementation of a multilayer structure utilizing the spin Seebeck effect (SSE) in a bilayer structure with a non-magnetic metal layer and a magnetic insulator layer, combined with field modulation techniques, to detect light across a broad wavelength range of 390 nm to 2200 nm, generating a spin current that produces an electrical voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional charge-based optoelectronic devices are used, then device architecture is well-established, but spin functionality cannot be effectively incorporated and broadband light detection is limited
Solution Approach 1:
The patent replaces traditional charge-based optoelectronic mechanisms with spin-based mechanisms. Specifically, it uses the spin Seebeck effect to generate spin current from thermal gradients, and the inverse spin Hall effect to convert spin current into measurable voltage signals. This substitution enables broadband light detection capability while maintaining a relatively simple bilayer structure consisting of a non-magnetic metal layer and a magnetic insulator layer, thus achieving high adaptability without excessive complexity
Solution Approach 2:
The patent creates a universal detection platform that can detect light across a broad wavelength range (390 nm to 2200 nm) using a single bilayer structure. The device performs multiple functions: it detects optical signals, operates across diverse wavelengths, and can be integrated into various applications including telecommunications, imaging, and sensing. This multi-functionality is achieved through the universal applicability of the spin Seebeck effect in converting thermal energy to electrical energy via spin currents
2Adaptability or versatility
If conventional light detection methods are used, then detection is achieved, but broadband detection capability and detection precision are insufficient
Solution Approach 1:
The patent changes the detection parameter from direct charge detection to spin current detection via thermal gradients. By measuring the voltage signal generated through the inverse spin Hall effect in response to spin current produced by the spin Seebeck effect, the system achieves precise detection across broadband wavelengths. The field modulation technique further enhances precision by allowing accurate measurement of the thermal gradient and spin current density
Solution Approach 2:
The patent introduces thermal energy as an intermediary to enable broadband detection. Light absorption generates thermal gradients in the non-magnetic metal layer, which then generate spin currents through the spin Seebeck effect. This intermediary thermal mechanism allows the system to detect a wide range of wavelengths that would be difficult to detect directly through charge mechanisms, while maintaining high detection precision through the voltage measurement
3Reliability
If spin current density measurement methods are used, then spin-based detection is enabled, but measurement complexity and device requirements increase
Solution Approach 1:
The patent simplifies spin current measurement by substituting complex direct spin current detection with voltage measurement through the inverse spin Hall effect. Instead of requiring complex setups to measure spin current density directly, the system converts spin current into a measurable voltage signal across a simple bilayer structure, thereby enabling reliable spin-based detection with reduced measurement complexity
Solution Approach 2:
The patent enables the device to self-measure spin current effects through the inherent voltage generation from the inverse spin Hall effect. The bilayer structure itself produces the measurable signal without requiring external complex measurement apparatus. The thermal gradient generated by light absorption automatically drives the spin current and voltage generation process, making the system self-sufficient and simplifying the overall measurement setup
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 featureless, broadband photodetection by thermally-generated spin currents, outperforming traditional devices in light detection capabilities and demonstrating the potential of spin-based devices as advanced optical detectors.
Implementation Method 1
The SSE occurs when a thermal gradient, VT, produces a pure spin current
Implementation Method 2
The spectral responsivity from about 390 nm to about 2200 nm is attributed to Pt absorption
Implementation Method 3
measuring spin current density primarily relies on either the inverse spin Hall effect (ISHE), which produces an electrical voltage from a spin current
Data Source
AI summary
Embodiments of the present disclosure generally relate to apparatus for and methods of detecting light utilizing the spin Seebeck effect (SSE). In an embodiment, a method for detecting broadband light is provided. The method includes generating a SSE in a device by illuminating the device with light, the device comprising a bilayer structure disposed over a substrate, the bilayer structure comprising a non-magnetic metal layer and a magnetic insulator layer. The method further includes measuring the SSE based on a field modulation method, determining, based on the measuring, an optically-created thermal gradient of the device, and detecting a wavelength range of the light. Apparatus for detecting broadband light are also described.