Raman Spectrometer Using Acousto-Optic Tunable Filter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Raman spectrometers are complex and expensive, limited in measuring large objects due to small photon currents and require high laser power, making them unsuitable for explosion-proof environments and unable to handle scattering or opaque samples effectively.
Innovation Solution
A spectrometer device using refractive optics for slit-free imaging with a tunable optical filter and single photon detectors, capable of detecting secondary light over a large area without wavelength dispersion, allowing for high sensitivity and low laser power operation, making it suitable for explosion-proof areas and opaque samples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high laser power is used to compensate for small photon currents, then detection sensitivity is improved, but the device becomes unsuitable for explosion-proof environments and safety is worsened
Solution Approach 1:
The patent replaces the conventional mechanical/optical dispersion system (gratings, prisms, slits) with an electronic tuning system using AOTF and SLM. This substitution eliminates the need for high laser power by enabling efficient spectral selection through acoustic and optical field control, thereby reducing explosion risks while maintaining detection sensitivity.
Solution Approach 2:
The patent changes the operational parameters by using tunable optical filters (AOTF, SLM) that can selectively transmit specific wavelengths with high efficiency. This parameter change allows the system to achieve sufficient signal intensity without increasing laser power, thus improving safety for explosion-proof environments.
2Measurement precision
If spatially dispersive elements are used to separate wavelengths, then wavelength resolution is improved, but the detectable area is limited to the size of detector pixels
Solution Approach 1:
The patent transitions from spatial dispersion to temporal/spectral dispersion by using AOTF and SLM. Instead of separating wavelengths spatially across detector pixels, the system uses acoustic and optical fields to filter wavelengths temporally, allowing the entire detector surface to contribute to detection and enabling measurement of large sample areas while maintaining wavelength resolution.
Solution Approach 2:
The patent replaces mechanical spatial dispersion elements (gratings, prisms, slits) with electronic spectral filtering systems (AOTF, SLM). This substitution eliminates the constraint of detector pixel size on the detectable area, as the entire detector surface can now be utilized for collecting light from large sample areas.
3Measurement precision
If conventional optical components are used, then wavelength separation is achieved, but device complexity and cost increase
Solution Approach 1:
The patent employs AOTF and SLM as multi-functional components that can perform spectral selection, wavelength tuning, and polarization control simultaneously. These universal components replace multiple separate optical elements (gratings, prisms, filters, slits), thereby reducing device complexity and cost while maintaining spectral analysis capability.
Solution Approach 2:
The patent replaces complex mechanical optical systems with electronically controlled AOTF and SLM systems. This substitution simplifies the device by eliminating mechanical moving parts, alignment mechanisms, and multiple discrete optical components, reducing both complexity and cost while preserving spectral analysis functionality.
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 solution enables high-quality spectral analysis with reduced complexity and cost, allowing for the measurement of larger samples and improved sensitivity, particularly in explosion-proof environments and with scattering or opaque samples.
Implementation Method 1
a wavelength-selective element in the form of an acousto-optical tunable filter (AOTF)
Implementation Method 2
A laser 30 radiates a primary light beam 32
Implementation Method 3
The detector device 58 comprises at least one single-photon detector 84, 84a, 84b
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a spectrometer apparatus, in particular a Raman spectrometer apparatus, a fluorescence spectrometer apparatus and/or an absorption spectrometer apparatus, a method for spectral analysis of a secondary light spectrum, in particular a Raman spectrum, a fluorescence spectrum and/or an absorption spectrum, and uses of such a spectrometer apparatus and the method. The spectrometer apparatus, in particular for Raman, fluorescence and/or absorption spectrometry comprises: a light source for generating primary light for illuminating a specimen so as to excite Raman scattering, fluorescence and/or absorption in the specimen by way of the primary light so that the specimen emits a secondary light spectrum, the secondary light spectrum being generated by Raman scattering of the primary light in the specimen, by fluorescence in the specimen and/or by absorption in the specimen; an optical system for projecting an emission region of the secondary light from the specimen; an optical filter, which filters the secondary light projected by the optical system; a control device for controlling the optical filter; a detector device which detects the secondary light filtered by the optical filter, the optical filter being formed as a variable optical filter in such a way that the wavelengths of the secondary light allowed to pass through to the detector device by the optical filter can be selected by means of controlling the variable optical filter by the control device.