CN209589851U - The long-range Raman detector of near infrared band based on GaAs bilayer image intensifier - Google Patents

Abstract

The utility model provides a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier, mainly includes 785nm nanosecoud pulse laser, narrow band filter, collects object lens, grating spectrograph, GaAs image intensifier, gating module, tfi module, coupled lens and ccd detector.The utility model is a kind of long-range Raman detection technology of near infrared band, has the advantages such as detection range is remote, the interference of lossless detection, non-cpntact measurement, high sensitivity, fluorescence is small, signal-to-noise ratio is high in the application such as agricultural, tobacco, food, medicine, criminal investigation, customs, safety check, blood testing.

Description

The long-range Raman detector of near infrared band based on GaAs bilayer image intensifier

Technical field:

The utility model relates to a kind of long-range Raman detectors of near infrared band, more particularly to one kind to be based on bilayer GaAs The long-range Raman detector of the near-infrared of image intensifier.

Background technique:

Raman spectrum is one kind based on light and the inelastically scattered scattering spectrum of molecule, reflects intramolecule vibration, turns The information such as dynamic, are a kind of species analysis " Fingerprint ".Raman spectrum has the characteristics that efficient, quick, non-destructive testing, simultaneously The information such as substance classes, ingredient, impurity, uniformity in detectable sample.And the absorption band of most of organic substances is not close red Exterior domain, therefore the interference of the fluorescence of Near-infrared Raman spectroscopy is smaller.Therefore near-infrared Raman region can be obtained CH, NH abundant, OH, The information of the groups such as SH, the advantages such as strong to sample penetration ability, so in agricultural, tobacco, food, medicine, criminal investigation, customs, blood The fields such as liquid detection are widely used.

But current near infrared band Raman is limited its application there is also some problems:

1) Raman scattering intensities and the biquadratic of optical maser wavelength are inversely proportional, thus the raman scattering intensity of near-infrared excitation laser compared with It can be seen that wanting weak with ultraviolet Raman signal；

2) quantum efficiency of conventional near infrared from detecting is lower, and Raman signal detection efficient is low；

3) for existing near-infrared Raman using continuous laser as excitaton source, operating distance is several millimeters, is contacted with sample close easy Contaminated samples.

Summary of the invention

In order to solve the above technical problems, the utility model provides a kind of near-infrared wave based on GaAs bilayer image intensifier Duan Yuancheng Raman detector, with detection range, remote, lossless detection, non-cpntact measurement, high sensitivity, fluorescence interfere small, noise Than high advantage, there is important application in the application such as agricultural, tobacco, food, medicine, criminal investigation, customs, blood testing.

A kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier described in the utility model, it is main It to include 785nm nanosecoud pulse laser, narrow band filter collects object lens, grating spectrograph, and GaAs image intensifier gates mould Block, tfi module, coupled lens, ccd detector.

Wherein, 785 nanosecoud pulse lasers, as the lighting source of object to be measured, for exciting target Raman Scattered signal；The narrow band filter, for filtering the elastic scattering light of 785nm；The mobile phone object lens, for collecting sample The Raman signal of product scattering, improves system collection efficiency；The grating spectrograph, the frequency domain point for collected Raman signal Analysis；The GaAs image intensifier, the gain near infrared light signal are amplified；The gating module, for controlling GaAs picture The gate opening time of booster realizes hatch bandwidth signals gating；The tfi module, for control GaAs image intensifier when Sequence is realized and is controlled with the timing synchronization of 785 nanosecoud pulse lasers；Coupled lens, for by GaAs image intensifier fluorescent screen Optical signal is coupled to ccd detector；Ccd detector, the acquisition for optical signal.

Beneficial effect

1, it is had the advantages that relative to visible or uv raman spectroscopy technology, Near-infrared Raman spectroscopy

(1) fluorescence of near infrared band, most of organic samples is not excited, and fluorescence interference is small；

(2) near-infrared laser is strong through ability.

2, using ps pulsed laser and ns pulsed laser as excitaton source, the operating mode progress with range gating is controlled by timing synchronization Raman spectrum analysis, laser transmission characteristic is good, can effectively avoid the advantages such as environment interference of stray light, is particularly suitable for distant object Non-contact, nondestructive detecting.

3, optical gain is carried out using GaAs image intensifier, quantum efficiency is high, optical gain is big, be suitble to distant signal and Infant laser signal detection, detectivity is high, signal-to-noise ratio is strong.

Detailed description of the invention

Near infrared band long-range Raman detector of the attached drawing 1 based on GaAs bilayer image intensifier.

Appended drawing reference is as follows:

101-785nm nanosecoud pulse laser, 102- narrow band filter, 103- collection object lens, 104- grating spectrograph, 105-GaAs bilayer image intensifier, 106- gating module, 107- tfi module, 108- coupled lens, 109-CCD detector.

Specific embodiment

As shown in Figure 1, a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier, main To include 785nm nanosecoud pulse laser 101, narrow band filter 102, collect object lens 103, grating spectrograph 104, GaAs bilayer Image intensifier 105, gating module 106, tfi module 107, coupled lens 108 and ccd detector 109.

Its working principles are as follows:

The gate width setting that GaAs bilayer image intensifier 105 is completed by gating module 106, utilizes tfi module 107 The timing synchronization of 785nm nanosecoud pulse laser 101 Yu GaAs bilayer image intensifier 105 is set.785nm nanosecoud pulse laser After the low repetition ps pulsed laser and ns pulsed laser of 101 outgoing, Raman scattering is excited after getting to object to be measured.Narrow band filter 102 first filters out The interference of 785nm laser signal in Raman scattering signal, then enter grating spectrograph 104 after collecting object lens 103.Grating spectrum The complex light that 104 pairs of collection object lens 103 of instrument are emitted carries out frequency domain light splitting, forms the monochromatic light of linear distribution.Monochromatic light reaches Optical-to-electronic conversion occurs for the photocathode of GaAs bilayer image intensifier 105, forms photoelectron；Photoelectron amplifies through the double-deck microchannel plate Afterwards, gain amplification electron is formed；After gain on electron bombardment to the fluorescent screen of GaAs bilayer image intensifier 105, electrical-optical occurs and turns Change, ultimately forms the optical signal of gain.The optical signal of fluorescent screen is coupled to CCD detection by the coupled lens 108 of gain optical signal On the target surface of device 109, ccd detector 109 carries out the acquisition of Raman optical signal.

A kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier, passes through timing synchronization Control GaAs bilayer image intensifier carries out " enabling " gating in the time that Raman signal reaches, and environment stray light and back is effectively reduced The interference of scape fluorescence, improves Raman signal signal-to-noise ratio；Quantum efficiency height, the optical gain in near-infrared of GaAs bilayer image intensifier By force, it is suitble to distant object and infant laser signal detection；Near-infrared laser excitation, the fluorescence of sample are not easy to be excited, and spectrum is clean.

To sum up, a kind of long-range Raman detection of near infrared band based on GaAs bilayer image intensifier described in the utility model Instrument has the advantages such as detection range is remote, the interference of lossless detection, non-cpntact measurement, high sensitivity, fluorescence is small, signal-to-noise ratio is high, in agriculture The application such as industry, tobacco, food, medicine, criminal investigation, customs, blood testing has important application.

In addition, it should be understood that although this specification is described in terms of embodiments, but not each embodiment is only wrapped Containing an independent technical solution, this description of the specification is merely for the sake of clarity, and those skilled in the art should It considers the specification as a whole, the technical solutions in the various embodiments may also be suitably combined, forms those skilled in the art The other embodiments being understood that.

Claims (10)

1. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier characterized by comprising nanosecond Pulse laser, narrow band filter, collect object lens, grating spectrograph, GaAs bilayer image intensifier, gating module, tfi module, Coupled lens and ccd detector；

The nanosecoud pulse laser, as the lighting source of object to be measured, for exciting target Raman scattering signal；

The narrow band filter, for filtering the elastic scattering light of Raman scattering signal, removal interference；

The collection object lens improve system collection efficiency for collecting the Raman signal of elastic scattering light；

The grating spectrograph, the Raman signal for collecting to the collection object lens carry out frequency domain light splitting, form linear point The monochromatic light of cloth；

The GaAs bilayer image intensifier, for carrying out gain amplification to the monochromatic light；

Coupled lens, for the optical signal on GaAs image intensifier fluorescent screen to be coupled to ccd detector；

Ccd detector, the acquisition for optical signal；

The gating module realizes hatch bandwidth signals gating for controlling the gate opening time of GaAs image intensifier；When described Sequence module is realized and is controlled with the timing synchronization of nanosecoud pulse laser for controlling the timing of GaAs image intensifier.

2. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the nanosecoud pulse laser, repetition rate 1-20Hz, wavelength 785nm, pulse width < 10ns, have outer Arousal function.

3. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the narrow band filter, central wavelength 785nm, bandwidth ± 10nm.

4. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the collection object lens, operation wavelength 400-1200nm.

5. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the grating spectrograph, grating line 1200lp, blaze wavelength 600nm optimize spectrum 400- 1200nm。

6. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the GaAs bilayer image intensifier, is increased using Dutch Photonics company PP3360G model GaAs bilayer picture Strong device, quantum efficiency > 30%@(500-800) nm, 80000 times of@600nm of typical greatest optical gain, internal high-voltage gain mould Block.

7. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the gating module, most short gating time: 3ns, shake < 30ps.

8. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the tfi module, maximum external trigger frequency: 125MHz, temporal resolution: 10ps, pulse width: 2ns- 10s。

9. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the coupled lens, service band 400-1200nm, imaging scale 1:1, F/# 1.4.

10. a kind of long-range Raman detector of near infrared band based on GaAs bilayer image intensifier according to claim 1, It is characterized in that, the ccd detector, using German Image Source company DMK33UX174 type detector, resolution ratio: 1920*1200, pixel dimension: 5.86 μm, frame frequency: 162fps.