CN211505195U - Device for realizing double-beam pumping in femtosecond transient absorption spectrometer - Google Patents

Abstract

The utility model discloses a device that is arranged in femto second transient absorption spectrometer to realize two pumping, the device comprises beam splitter, light intensity attenuator, focusing lens (or focusing mirror), plane mirror. The device realizes secondary pumping of a sample in a detection period by additionally introducing a pumping light optical path into a normal femtosecond transient absorption spectrometer, thereby providing convenience for researching secondary excitation dynamics of a sample detection region under the condition of being in an excited state. The utility model provides a device can carry out the spectral dynamics detection of secondary excitation on the basis of the pumping-detection technique of femto second transient state absorption spectrum, has widened the range of application of transient state absorption spectrum technique, provides the powerful tool for the research that relates to excited state dynamics in physics, chemistry, biology.

Description

Device for realizing double-beam pumping in femtosecond transient absorption spectrometer

Technical Field

The utility model relates to a device that is arranged in femto second transient absorption spectrometer to realize two pumping belongs to spectral measurement technical field.

Background

The femtosecond transient absorption spectrum technology is a time-resolved absorption spectrum, utilizes femtosecond pulse light as a light source, can obtain the change condition of the absorption spectrum of an excited state of a sample in an ultrafast time scale, and belongs to a typical pumping-detection spectrum technology. The method is widely applied to scientific research activities in the fields of physics, chemistry, biology and the like. The device can use the mature femtosecond laser technology and the nonlinear optical technology as the technical foundation, and has the advantages of high time resolution, adjustable spectrum detection range and the like. Particularly, the method has a sub-picosecond time resolution function, and shows great advantages in the research fields of charge transfer detection, separation, energy transfer dynamics and the like.

Because the conventional femtosecond transient absorption spectrometer can only measure the excited state dynamics of a sample after one-time excitation, the method has great limitation on the detection of the sample with complex dynamic behavior. For example, conventional pump-detection techniques are difficult to observe for excited state systems with multiple consecutive relaxation processes. Therefore, how to widen the application range of the femtosecond transient absorption spectrometer and how to more flexibly detect more complex excited state dynamics is an urgent need in the scientific research field. In response to this problem, it is necessary to modify the conventional transient absorption spectrometer to enable more flexible pump-probe experiments, and the device for increasing the pump beam is an important modification.

Disclosure of Invention

The utility model overcomes the narrower problem of conventional femto second transient absorption spectrum appearance range of application provides a device that is arranged in femto second transient absorption spectrum appearance to realize two bundles of pumping, has solved femto second transient absorption spectrum appearance and has been used for the detection of the excitation state dynamics that the part is more complicated.

In order to solve the technical problem, the utility model discloses a following technical scheme:

a device for realizing double-beam pumping in a femtosecond transient absorption spectrometer can realize the functions of pumping-re-pumping-detection on the basis of realizing the pumping-detection function of the existing femtosecond transient absorption spectrometer. On the basis of a femtosecond transient absorption spectrometer with a normal pumping-detection function, a light path for a second beam of pumping light to travel is additionally added, wherein the light path comprises: beam splitter, light intensity attenuator, focusing lens (or focusing reflector) and plane reflector.

The beam splitting sheet can realize the functions of partial transmission and partial reflection of laser beams, and the specific transmission-reflection ratio can be determined according to scientific research requirements.

The light intensity attenuator can realize the adjustment of the laser intensity, thereby changing the excitation power of the sample.

The focusing lens (or the focusing reflector) can realize the focusing of parallel light, the selection of the focal length is suitable for the space of the spectrometer, and the proper light spot area can be generated on a sample.

The beam splitter can realize the functions of partial reflection and partial transmission of laser, so that the reflected light can be used as second pump light.

The light intensity attenuator can realize the attenuation of the laser intensity, thereby realizing the adjustment of the excitation power of the second beam of pump light.

The focusing lens (or focusing reflector) can realize the focusing of parallel light, thereby reducing the area of the pump light at the sample.

The plane reflector can change the light propagation direction.

The double-beam pumping device for the transient absorption spectrometer can realize the functions of pumping-re-pumping-detecting and has other equivalent optical path arrangements.

The reflector can change the propagation direction of laser rays and can finely adjust the direction.

This additional added optical path may allow for the addition of a pump at a point in time prior to the pump-detect process. The device provides a useful extension to scientific research activities using pump-probe technology, as additional pumping times can increase the dynamic behavior of the sample.

The device realizes secondary pumping of a sample in a detection period by additionally introducing a pumping light optical path into a normal femtosecond transient absorption spectrometer, thereby providing convenience for researching secondary excitation dynamics of a sample detection region under the condition of being in an excited state. The utility model provides a device can carry out the spectral dynamics detection of secondary excitation on the basis of the pumping-detection technique of femto second transient state absorption spectrum, has widened the range of application of transient state absorption spectrum technique, provides the powerful tool for the research that relates to excited state dynamics in physics, chemistry, biology.

Drawings

Fig. 1 is a schematic diagram of the principle of the present invention.

Fig. 2 is a schematic diagram of a typical femtosecond transient absorption spectrometer to which the present invention is applied (the device of the light path thickening portion is the present invention).

Detailed Description

The utility model provides a typical implementation scheme that is arranged in femto second transient absorption spectrometer to realize device of two bundles of pumping is shown in figure 2, and the light path adds the thick portion to be for the utility model discloses the schematic diagram of using in the transient absorption spectrometer realizes the beam splitting of original pumping light path promptly and realizes the secondary pumping. Specifically, the second beam of pump light reaches the sample at a proper delay time after passing through the beam splitting sheet, the attenuation sheet, the convex lens and the reflector in sequence after passing through the pump light outlet after frequency adjustment.

The principle of the transient absorption spectroscopy technique is to detect the difference in absorbance at each delay time at each wavelength over a spectral range for the sample, both pumped and unpumped. In the setting of the present invention, as shown in fig. 1, the principle of this kind of secondary pumping-detection technique is to detect the difference in absorbance of the sample at each wavelength under each delay time under the condition of the secondary pumping and the primary pumping.

In fig. 2, the beam splitter (beam splitter) is semi-transparent and semi-reflective.

In fig. 2, the attenuation sheet (light intensity attenuator) can realize continuous adjustment of attenuation intensity, and the maximum attenuation intensity is 4OD, so as to adjust the excitation intensity of additional pump light.

In fig. 2, the convex lens (focusing lens) can focus laser light, and the selected focal length is 500 mm.

In fig. 2, the reflector (plane mirror) is an aluminized plane mirror, which can change the direction of the light path, and can be finely adjusted in direction by a knob on the mirror holder, so that an additional pump beam is focused on the detection point of the sample.

As shown in FIG. 2, the additional pumping light path is split from the original pumping light path and sequentially passes through a beam splitter, a light intensity attenuator, a focusing lens and a plane mirror. The optical path finally realizes an additional primary pumping.

The extra pumping optical path can adjust the time for two pumping optical pulses to reach the sample by increasing or shortening the optical path, so that the applicability of the method is greatly enhanced.

The above-mentioned embodiment does not restrict in any way the utility model discloses, all adopt other modes to realize that the femto second transient state absorption spectrum technical scheme of the secondary pumping of the detection principle that fig. 1 shows all falls the utility model discloses a within the scope of protection.

Claims (4)

1. A device for realizing double-beam pumping in a femtosecond transient absorption spectrometer is characterized in that,

the method comprises the steps that light emitted by a femtosecond transient absorption spectrometer is divided into two beams by a beam splitter;

one beam of light passes through a plane reflector, a delay lens group consisting of four plane reflectors for vertically refracting the light, and then passes through two plane reflectors and irradiates on a sample;

the other beam of light changes the frequency into proper wavelength for pumping, is divided into a second beam and a third beam by a beam splitting sheet after passing through a plane mirror, the second beam of light irradiates a sample after passing through a chopper, and the third beam of light irradiates the sample after passing through a light intensity attenuator, a focusing lens or a focusing mirror and the plane mirror.

2. The apparatus of claim 1, wherein:

irradiating light on the sample; the optical signal on the sample is transmitted to the computer through the signal detected by the detector.

3. The apparatus of claim 1, wherein: the focusing lens is a focusing convex lens.

4. The apparatus of claim 1, wherein: the light intensity attenuator is an attenuation sheet.

Images