CN203824653U - Femtosecond laser pulse width measuring instrument based on molecular ionization detection - Google Patents

Abstract

The utility model discloses a femtosecond laser pulse width measuring instrument based on molecular ionization detection. The laser pulse beam passes through the beam splitter to form two beam channels, the femtosecond laser pulse beam passing through the plane high reflection mirror C in the first beam channel and the femtosecond laser pulse passing through the plane high reflection mirror F in the second beam channel After the beam passes through the beam combiner, under the action of the focusing lens, it precisely coincides with the ultrasonic molecular beam of the time-of-flight mass spectrometer. The utility model is simple and practical, convenient to adjust, fast in data collection and data processing, and can adapt to the measurement and real-time monitoring of femtosecond laser pulse width and pulse shape with different pulse widths and different wavelengths.

Description

A Femtosecond Laser Pulse Width Measuring Instrument Based on Molecular Ionization Detection

technical field

The utility model relates to a measuring device for femtosecond laser pulse optical parameters, in particular to a femtosecond laser pulse width measuring instrument based on molecular ionization detection.

Background technique

The research on femtosecond laser and corresponding femtosecond laser technology has developed rapidly with the expansion and deepening of the application of femtosecond laser pulses in scientific research, biology, medical treatment, processing, communication, national defense and other social fields. One of the important applications is the use of femtosecond laser pulses and femtosecond laser spectroscopy to study ultrafast dynamics in various materials such as proteins, nanomaterials, and semiconductors. For example, femtosecond pump-probe technology and femtosecond stimulated Raman scattering technology can be used to study protein structural dynamics, semiconductor and nanomaterial carrier dynamics. On the other hand, the pulse shape and pulse width of femtosecond laser is an important optical parameter in the application of femtosecond laser pulse, and its measurement or real-time monitoring is very necessary in many experiments and applications. At present, two important methods of pulse measurement are frequency-resolved optical grating (FROG) method and self-referenced spectral interferometry (SRSI) method, but the above two measurement methods are based on optoelectronic The pulse measurement method of the detector, and the photodetector has a certain frequency response range, so the method of using the traditional optical detector to measure the optical parameters of the femtosecond laser pulse is limited to the frequency of the laser to be measured.

Contents of the invention

The technical problem solved by the utility model is to provide a femtosecond laser pulse width measuring instrument based on molecular ionization detection, which is simple and practical, convenient to adjust, and fast in data acquisition and data processing. The device can use the interference effect of light and laser ionized molecules To measure complex optical parameters of femtosecond laser pulses.

The technical scheme of the utility model is: a femtosecond laser pulse width measuring instrument based on molecular ionization detection, including a femtosecond laser pulse beam emitting source, characterized in that: There is a beam splitter, and the femtosecond laser pulse beam passes through the beam splitter to form two beam channels, of which the first beam channel is provided with a plane high reflection mirror A, a plane high reflection mirror B and a plane high reflection mirror in sequence along the beam advancing direction C, the second beam channel is sequentially provided with a plane high reflection mirror D, a plane high reflection mirror E and a plane high reflection mirror F along the beam advancing direction, and the plane high reflection mirror B and the plane high reflection mirror C are set at high precision A high-precision optical delay platform is formed on the electric translation stage, and the femtosecond laser pulse beam passing through the plane high reflection mirror C in the first beam channel and the femtosecond laser pulse beam passing through the plane high reflection mirror F in the second beam channel are combined After the beam sheet is precisely overlapped with the ultrasonic molecular beam of the time-of-flight mass spectrometer under the action of the focusing lens, the focusing lens is arranged behind the beam combining sheet, the time-of-flight mass spectrometer is arranged behind the focusing lens, and the time-of-flight The mass spectrometer includes an ultrasonic molecular beam system, a beam source chamber, an ionization chamber, an ion lens, and a microchannel plate detector. The ultrasonic molecular beam system is mainly composed of a carrier gas device, an intake pipe, and a sample cell. The intake pipe is connected, and the beam source chamber is connected with the sample cell through the intake pipe. The end of the intake pipe is provided with a pulse valve, and the molecular pump A is connected under the beam source chamber, and the molecular pump A is connected with the mechanical pump A. The ionization cavity is arranged on one side of the beam source cavity, and a molecular pump B is connected to the bottom of the ionization cavity, and the molecular pump B is connected to the mechanical pump B. An ion lens is arranged in the ionization cavity, and the ion lens includes Pole plate A, pole plate B, and pole plate C are arranged in parallel in sequence in the advancing direction, and the microchannel plate detector is set in a direction opposite to the ion lens.

The utility model utilizes Labview to realize the automatic control of the signal inputted by the high-precision electric translation platform and the micro-channel plate detector into the acquisition card.

The utility model has the following beneficial effects: 1. Use the interference effect of light to measure the complex femtosecond laser pulse width; 2. The utility model has a simple structure, and only a few plane high reflection mirrors can be used for pulse measurement and pumping The detection experiment reduces the stability impact brought by the optical elements and improves the reliability and stability of the system; 3. Compared with the previous device, the device of the present invention mainly detects molecules by femtosecond laser ionization, so it is significantly The frequency range of femtosecond laser pulse measurement has been greatly improved, and the measurement of laser pulses from the period level to hundreds of femtoseconds in the deep ultraviolet to mid-infrared ultra-broadband spectral range can be realized.

Description of drawings

Fig. 1 is the optical path structure schematic diagram of the present utility model, and Fig. 2 is the experimental result figure of the approximately 50 fs laser pulse of 800 nm central wavelength of the present utility model.

Drawing description: 1. Femtosecond laser pulse beam emission source, 2. Beam splitter, 3. Plane high reflection mirror A, 4. Plane high reflection mirror B, 5. Plane high reflection mirror C, 6. High-precision electric translation Platform, 7. Plane highly reflective mirror D, 8. Plane highly reflective mirror E, 9. Plane highly reflective mirror F, 10. Beam combiner, 11. Focusing lens, 12. Time-of-flight mass spectrometer, 13. Ultrasonic molecular beam system , 14. Beam source chamber, 15. Ionization chamber, 16. Ion lens, 17. Microchannel plate detector, 18. Carrier gas device, 19. Sample cell, 20. Intake pipe, 21. Pulse valve, 22. Molecule Pump A, 23, Molecular pump B, 24, Mechanical pump A, 25, Mechanical pump B, 26, Pole plate A, 27, Pole plate B, 28, Pole plate C.

Detailed ways

Embodiments are described in detail with reference to the accompanying drawings. A femtosecond laser pulse width measuring instrument based on molecular ionization detection, comprising a femtosecond laser pulse beam emitting source 1, a beam splitter 2 is arranged on the same horizontal plane opposite to the femtosecond laser pulse beam emitting source 1, and the femtosecond laser pulse beam After the beam passes through the beam splitter 2, two beam channels are formed, wherein the first beam channel is sequentially provided with a plane high reflection mirror A 3, a plane high reflection mirror B 4 and a plane high reflection mirror C 5 along the beam advancing direction, and the second one The beam channel is provided with a plane high reflection mirror D 7, a plane high reflection mirror E 8 and a plane high reflection mirror F 9 successively along the light beam advancing direction, and the plane high reflection mirror B 4 and the plane high reflection mirror C 5 are arranged at high precision A high-precision optical delay platform is formed on the electric translation platform 6, and the plane high-reflection mirror B 4 and the plane high-reflection mirror C 5 are driven by the high-precision electric translation platform 6 to move forward and backward with high precision along the beam direction, and pass through the first beam channel The femtosecond laser pulse beam of the mid-plane high reflection mirror C 5 and the femtosecond laser pulse beam of the mid-plane high reflection mirror F 9 passing through the second beam channel pass through the beam combiner 10 and combine with the time-of-flight mass spectrometer under the action of the focusing lens 11 The ultrasonic molecular beams of the instrument 12 are precisely overlapped, the focusing lens 11 is arranged behind the beam combining plate 10, and the time-of-flight mass spectrometer 12 is arranged behind the focusing lens 11, and the described time-of-flight mass spectrometer 12 includes an ultrasonic molecular beam system 13. A beam source chamber 14, an ionization chamber 15, an ion lens 16 and a microchannel plate detector 17, wherein the ultrasonic molecular beam system 13 is mainly composed of a carrier gas device 18, an air inlet pipe 20 and a sample cell 19, and the carrier gas device 18 and The sample pool 19 is connected to each other through the intake pipe 20, the beam source chamber 14 is connected to the sample pool 19 through the intake pipe 20, the end of the intake pipe 20 is provided with a pulse valve 21, and the beam source chamber 14 is connected with a molecular pump below A 22, the molecular pump A 22 is connected with the mechanical pump A 24, the ionization chamber 15 is arranged on one side of the beam source chamber 14, the molecular pump B 23 is connected under the ionization chamber 15, the molecular pump B 23 and the mechanical pump B 25 is connected, and ion lens 16 is provided in ionization cavity 15, and this ion lens 16 comprises pole plate A 26, pole plate B 27 and pole plate C 28 that are arranged in parallel along the advancing direction of ultrasonic molecular beams successively, and described microchannel plate The detector 17 is arranged in the direction opposite to the ion lens 16, and the ions formed by the ionization of molecules fly to the microchannel plate detector 17 under the action of the electric field, and finally connect with the acquisition card on the computer through a coupling circuit. The utility model utilizes Labview to realize the automatic control of the signal inputted by the high-precision electric translation platform 6 and the microchannel plate detector 17 into the acquisition card.

Using this measuring device to measure laser pulses with a center wavelength of 800 nm of about 50 fs, the measurement results are shown in Figure 2. Therefore, this device can be used to measure the period level of the ultra-broadband spectral range from deep ultraviolet to near infrared to hundreds of femtoseconds measurement of laser pulses.

The basic principles, main features and advantages of the present utility model have been shown and described above. On the premise of not departing from the spirit and scope of the present utility model, the present utility model also has various changes and improvements, and these changes and improvements all fall into the claims. The scope of the utility model.

Claims (1)

1. a femtosecond laser pulse width measuring instrument of surveying based on molecular ionization, comprise femto-second laser pulse radiation beam source, it is characterized in that: the same level relative with femto-second laser pulse radiation beam source is provided with beam splitting chip, femto-second laser pulse light beam forms twice beam channel after beam splitting chip, wherein first beam channel is provided with plane high reflection mirror A successively along light beam working direction, plane high reflection mirror B and plane high reflection mirror C, second beam channel is provided with plane high reflection mirror D successively along light beam working direction, plane high reflection mirror E and plane high reflection mirror F, described plane high reflection mirror B and plane high reflection mirror C are arranged at and on high-precision electric translation stage, form high-precision optical and postpone platform, by the femto-second laser pulse light beam of first beam channel midplane high reflection mirror C and the femto-second laser pulse light beam by second beam channel midplane high reflection mirror F after closing bundle sheet under the effect of condenser lens with the ultrasonic molecular beam inregister of time of-flight mass spectrometer, described condenser lens is arranged at the rear of closing bundle sheet, time of-flight mass spectrometer is arranged at the rear of condenser lens, described time of-flight mass spectrometer comprises ultrasound molecular beam system, electron gun chamber, ionization chamber, ion lens and micro-channel plate detector, wherein ultrasound molecular beam system is mainly by carrier gas device, admission line and sample cell form, carrier gas device is connected by admission line with sample cell, electron gun chamber is connected with sample cell by admission line, the end of this admission line is provided with pulse valve, the below in electron gun chamber is connected with molecular pump A, molecular pump A is connected with mechanical pump A, described ionization chamber is arranged at a side in electron gun chamber, the below of ionization chamber is connected with molecular pump B, molecular pump B is connected with mechanical pump B, in ionization chamber, be provided with ion lens, this ion lens comprises the pole plate A be arrangeding in parallel successively along ultrasonic molecular beam working direction, pole plate B and pole plate C, described micro-channel plate detector is arranged in the direction relative with ion lens.