Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Detecting species in a dilute medium

一种介质、物质的技术，应用在检测气体样品或大气中的分子物质领域

Active Publication Date: 2012-09-12
PRINCETON UNIV TRUSTEESHIP
View PDF4 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this system is not particularly suitable for dilute substances because the signal can be masked by noise and other factors

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Detecting species in a dilute medium
  • Detecting species in a dilute medium
  • Detecting species in a dilute medium

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0047] Quantum cascade lasers (QCLs) have been used to measure the absorption signal of molecular gases in specific fingerprint regions. These implementations of QCL-based tunable laser absorption spectroscopy are mainly based on trace gas detection and / or real-time gas monitoring via laser intensity changes. The present invention instead uses refractive index changes to measure substances in dilute media, especially gases or air.

[0048] Especially for dilute mixtures, this change in refractive index can be very small and susceptible to higher levels of noise. figure 1 A schematic diagram of a system 10 for detecting species in dilute media is shown, which exploits the phenomenon of refractive index change as described above. The QCL 20 is tunable and can be chirped (ie, the wavelength varies within a period) by the controller 25 . The laser beam from the QCL is split into two laser beams using an acousto-optic modulator (AOM) 30 driven by a radio frequency (RF) source 40 ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

Method and apparatus (10) for detecting a species in a dilute medium, the species having a spectral feature, the apparatus comprising: a beam source (20) arranged to generate a first laser beam and a second laser beam coherent with each other, and having a matching chirp pattern. Beam guide arranged to pass at least the first laser beam through the dilute medium; a beam mixer arranged to mix the first and the second laser beams to form a mixed beam. Detector (80) arranged to detect, during the chirp pattern, the mixed beam and to measure changes in the mixed beam caused by refractive index variations in the dilute medium across a spectral feature. Output providing a signal that changes in response to the measured changes.

Description

technical field [0001] The present invention relates to methods and devices for detecting substances in dilute media, especially molecular substances in gaseous samples or the atmosphere. Background technique [0002] Absorption spectroscopy and fluorescence spectroscopy are commonly used to detect the presence of specific chemical species in a range of samples, especially in dilute media such as gases. Absorption of narrowband laser light by specific molecular transitions can be detected by a decrease in detected intensity or amplitude, especially in the ultraviolet or visible spectrum. Absorption of broadband light may be due to one or more molecular transitions and may also be detected by spectral analysis of the light. Similarly, fluorescence originating from excited molecular states can also be detected. [0003] However, such techniques typically rely on amplitude detection and are therefore susceptible to flicker and laser noise. [0004] "Resonant, heterodyne-lase...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G01N21/35G01N21/39G01N21/45
CPCG01N21/45
Inventor 达米安·魏德曼G·威索基
Owner PRINCETON UNIV TRUSTEESHIP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com