CN204479181U - A kind of parallel double grating monochromator - Google Patents

Abstract

The utility model discloses a parallel double grating monochromator which comprises a frame, on which a first grating and a second grating arranged in parallel are installed, and a rotating shaft is arranged on the frame; A sinusoidal drive mechanism that rotates coaxially with the second grating, and the sinusoidal drive mechanism is transmission-connected to the rotation shaft. The above structure of the utility model makes the sinusoidal drive mechanism drive the rotating shaft to rotate, and the rotating shaft drives the frame to rotate as a whole, so that the first grating and the second grating installed on the frame rotate simultaneously and synchronously. Therefore, the first grating and the second grating of the utility model have achieved the effect of synchronous rotation. At the same scanning speed, the measurement speed is doubled compared with that of a single grating during full-band scanning; at the same time, the wavelength of the separated monochromatic light The range is doubled and the spectral energy is evenly distributed.

Description

A Parallel Double Grating Monochromator

technical field

The utility model relates to the technical field of spectrum analysis instruments, in particular to a parallel double grating monochromator.

Background technique

Grating monochromator is an optical instrument for high-resolution analysis and selection of photon energy or wavelength. It is an integrated spectral analysis and measurement instrument for subordinate research in the fields of optics and optoelectronics. A grating monochromator uses a grating as a spectroscopic element to decompose the incident composite light into monochromatic light with a narrow spectral width that can be arbitrarily selected across the entire band, that is, the grating monochromator decomposes the composite light into a series of high An instrument for the purity of monochromatic light. According to the characteristics of the monochromatic light source produced by the grating monochromator, it is used for qualitative and quantitative analysis of transparent substances and solutions. The advantage of the grating monochromator is that the range of the wavelength band is wide, the dispersion is uniform in the whole band, and the wavelength of the monochromatic light can reach a very precise level.

However, during the use of the grating monochromator, sometimes multiple gratings are needed, or the gratings need to be replaced frequently. In order to solve the above problems, two simple monochromators are currently connected in series to form a double monochromator. In double monochromators, each monochromator has its own dispersion system with a certain dispersion rate. Two monochromators work together, and there are two different combinations: dispersion addition system and dispersion subtraction system. The double monochromator using the dispersion addition system can obtain a greater total dispersion rate; while the double monochromator using the dispersion subtraction system is only to obtain more "pure" monochromatic light and suppress stray light. The dynamic consistency of the two monochromators must be guaranteed when the dispersion-adding dual monochromators are scanning. Usually, a mechanism is used to control the relative movement of the two monochromators. Because of a slight difference, the decomposed light beams cannot all be emitted from the exit slit, and may even be completely blocked by the middle slit.

The driving mechanisms of the currently used double monochromators are mostly: linkage sinusoidal mechanisms or synchronously driven sinusoidal mechanisms. The above two sinusoidal mechanisms generally include two sinusoidal arms, which are set in one-to-one transmission connection with two gratings; and then the two sinusoidal arms are simultaneously driven by a driving component to make the two gratings move synchronously. But no matter how high the precision is, there will always be errors in the movement of the two gratings, which affects the synchronization of the two gratings, and cannot obtain more "pure" monochromatic light, nor can it suppress stray light.

Utility model content

The purpose of this utility model is to provide a parallel double-grating monochromator, the two gratings of the double-grating monochromator have good synchronization, obtain more "pure" monochromatic light, and also suppress stray light well, The spectral energy under full-band scanning is correspondingly flattened, thereby improving the measurement speed.

In order to solve the above technical problems, the technical proposal of the present utility model is: a parallel double-grating monochromator includes a frame, the first grating and the second grating arranged in parallel are installed on the frame, and a rotating shaft; further comprising a sinusoidal drive mechanism for driving the first grating and the second grating to rotate coaxially, and the sinusoidal drive mechanism is transmission-connected to the rotation shaft.

Preferably, there is a phase angle difference between the first grating and the second grating.

Preferably, the blaze wavelength of the first grating is different from the blaze wavelength of the second grating.

Preferably, the sinusoidal drive mechanism includes a sinusoidal arm, one end of the sinusoidal arm is in transmission connection with the rotating shaft, and the other end of the sinusoidal arm is in transmission connection with a sine mechanism top block, and the sine mechanism top block The block is drivingly connected to the output shaft of a stepper motor.

Preferably, the top block of the sinusoidal mechanism is a cam, and the cam is sheathed on the output shaft of the stepping motor.

Preferably, the double grating monochromator further includes a first entrance slit and a first exit slit corresponding to the first grating, and a second entrance slit and a second exit slit corresponding to the second grating seam.

Preferably, the frame is a rectangular frame, the first grating and the second grating are arranged in parallel along the length direction of the frame, and the rotation axis is arranged along the width direction of the frame.

After adopting the above-mentioned technical scheme, the beneficial effect of the utility model is: because the parallel double grating monochromator of the utility model comprises a frame, the first grating and the second grating are installed on the frame, and a rotating shaft is arranged on the frame, The above structure enables the two gratings to achieve the purpose of coaxial installation. The utility model also includes a sinusoidal driving mechanism for driving the first grating and the second grating to rotate coaxially, and the sinusoidal driving mechanism is connected with the rotating shaft through transmission. When the sine drive mechanism of the utility model drives the rotating shaft to rotate, the rotating shaft drives the frame to rotate as a whole, so that the first grating and the second grating installed on the frame at the same time achieve the purpose of coaxial rotation and synchronous rotation. Therefore, the first grating and the second grating of the utility model achieve the effect of synchronous rotation, obtain more "pure" monochromatic light, and suppress stray light well; The speed is doubled compared with a single grating; at the same time, the wavelength range of the separated monochromatic light is doubled, and the spectral energy distribution is uniform.

Because there is a phase angle difference between the first grating and the second grating, the structure makes the scanning wavelengths of the two gratings just coincide, thereby expanding the spectral range.

Since the blazed wavelength of the first grating is different from that of the second grating, this structure makes the two gratings equivalent to a double blazed grating, which makes the spectral energy response more flat during full-band scanning.

Since the sinusoidal driving mechanism includes a sinusoidal arm, one end of the sinusoidal arm is connected to the rotating shaft, and the other end of the sinusoidal arm is connected to a sinusoidal mechanism top block, and the sinusoidal mechanism top block is connected to the output shaft of a stepping motor. connection; when the stepping motor of this structure is rotating, the output shaft of the stepping motor drives the top block of the sinusoidal mechanism to rotate together, and the top block of the sinusoidal mechanism carries the sinusoidal arm for sinusoidal motion, and finally the rotating shaft takes the first grating and the second The two gratings rotate synchronously.

In summary, the utility model installs the first grating and the second grating on the same frame, and installs a rotating shaft on the frame, so that the two gratings can be coaxially installed; in order to achieve coaxial rotation, this The utility model allows the rotating shaft to be rotated by the sinusoidal drive mechanism, so that the two gratings can rotate coaxially, thereby obtaining relatively pure monochromatic light and improving the measurement speed of the utility model. Moreover, the utility model makes the spectral energy response more flat when the utility model scans the whole band by selecting a grating with no blazing wavelength. The utility model also allows the first grating and the second grating to maintain a certain installation phase angle difference after they are installed on the frame, thereby enlarging the spectral range.

Description of drawings

Fig. 1 is the structural representation when parallel double grating monochromator of the present utility model is in working position;

Fig. 2 is the structural representation when parallel double grating monochromator of the present utility model is in starting position;

Fig. 3 is the structural representation when the parallel double grating monochromator of the present invention is in the termination position;

In the figure: 1—the first grating, 2—the second grating, 3—the first entrance slit, 4—the first exit slit, 5—the second entrance slit, 6—the second exit slit, 7—sine Arm, 8—sinusoidal mechanism top block, 9—stepping motor, 10—rotating shaft, 11—frame.

Detailed ways

In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

As shown in FIG. 1 , FIG. 2 and FIG. 3 , a parallel double-grating monochromator includes a frame 11 , preferably the frame 11 is a rectangular frame. It also includes a first grating 1 and a second grating 2 arranged in parallel on the frame 11 , and the two gratings in this embodiment are arranged in parallel along the length direction of the frame 11 . A rotating shaft 10 is also provided on the frame 11 , and the rotating shaft 10 in this embodiment is arranged along the width direction of the frame 11 . The rotating shaft 10 of the double-grating monochromator of the present utility model is connected with a sinusoidal driving mechanism through transmission, that is, the rotating shaft 10 is driven by the sinusoidal driving mechanism to move sinusoidally, and the movement of the rotating shaft 10 makes the frame 11 move together, and finally makes the At the same time, the first grating 1 and the second grating 2 mounted on the frame 11 rotate coaxially.

The sinusoidal driving mechanism includes a sinusoidal arm 7 , one end of the sinusoidal arm 7 is in transmission connection with the rotating shaft 10 , and the other end of the sinusoidal arm 7 is in transmission connection with a sinusoidal mechanism top block 8 . The sinusoidal mechanism top block 8 is connected with the output shaft of a stepping motor 9 through transmission. Preferably, the top block 8 of the sinusoidal mechanism is a cam, and the cam is sleeved on the output shaft of the stepping motor 9 . When the output shaft of the stepping motor 9 is rotating, the cam is driven to rotate, and the sinusoidal arm 7 connected to the cam drive is moved sinusoidally, and the rotating shaft 10 connected to the sinusoidal arm 7 is moved sinusoidally together, finally The first grating 1 and the second grating 2 rotate coaxially.

There is a phase angle difference between the first grating 1 and the second grating 2 in this embodiment, and the phase angle difference makes the first grating 1 and the second grating 2 have a certain installation initial angle. However, the scanning wavelengths of the two gratings with phase angle difference are just connected, thus expanding the range of the spectrum. Preferably, the initial angle of the first grating 1 is 200°, and the initial angle of the second grating 2 is 600°. Then the scanning range of the first grating 1 is between 200°-600°, and the scanning range of the second grating 2 is between 600°-1000°. It is obvious that the first grating 1 and the second grating 2 are connected at 600° , thereby increasing the measurement speed.

The blaze wavelength of the first grating 1 and the blaze wavelength of the second grating 2 in this embodiment are different, wherein the blaze wavelength is the maximum blaze wavelength corresponding to the blaze angle in the blaze grating, and is also the strongest diffraction wavelength. In the utility model, two gratings with different blaze wavelengths can be selected to make it equivalent to a double blaze light, so that the spectral energy response is more flat during full-band scanning, and the wavelength range is doubled.

In addition, the double grating monochromator of this embodiment also includes a first entrance slit 3 and a first exit slit 4 corresponding to the first grating 1, and a second entrance slit 5 and a second exit slit corresponding to the second grating 2 Sew 6.

When the utility model is used for qualitative and quantitative analysis of transparent substances and solutions, the light beam emitted by the light source or the lighting system is uniformly irradiated on the first entrance slit 3 and the second entrance slit 5 at the same time, and after passing through other optical elements , are split by the first grating 1 and the second grating 2 respectively, and monochromatic light is split from the first exit slit 4 and the second exit slit 6 respectively. The stepping motor 9 of the sinusoidal drive mechanism of the utility model starts to work under the control of the control system, and the rotating speed can be adjusted according to the measurement needs of the control system. After the stepping motor 9 rotates, the sine mechanism top block 8 is taken with the rotating shaft, and the sine mechanism top block 8 moves against the sine arm 7 again, so that the sine arm 7 does a sinusoidal motion. Finally, the rotating shaft 10 also performs a sinusoidal motion, and the frame 11 rotates coaxially with the first grating 1 and the second grating 2 synchronously. After the coaxial rotation of the first grating 1 and the second grating 2, the monochromatic light from short wavelength to long wavelength appears sequentially from the first exit slit 4 and the second exit slit 6, and the monochromatic light is more pure, Stray light is reduced.

Since the starting point and the ending point of the first grating 1 and the second grating 2 of the present invention are at the same position, the measurement speed is improved. The two groups of gratings are synchronized in light splitting, with high precision and good effect. The two gratings obtain superposition of light energy to achieve monochromatic light with higher light energy. Therefore, compared with monochromators simply connected in series, the utility model doubles the measurement speed and doubles the wavelength range.

The preferred embodiment of the utility model described above is only, not in order to limit the utility model, any modification done within the spirit and principle of the utility model, is equal to the improvement of a kind of parallel double grating monochromator structure etc. , should be included within the protection scope of the present utility model.

Claims (7)

1. a parallel double grating monochromator, is characterized in that, comprises framework, and described framework is provided with the first grating and second grating of parallel setting, described framework is provided with a rotation axis; Also comprise the Sine Driving Mechanism for driving described first grating and described second grating coaxial rotation, described Sine Driving Mechanism and described rotation axis are in transmission connection.

2. parallel double grating monochromator according to claim 1, is characterized in that, has phase angle difference between described first grating and described second grating.

3. parallel double grating monochromator according to claim 1, is characterized in that, the blaze wavelength of described first grating is different with the blaze wavelength of described second grating.

4. parallel double grating monochromator according to any one of claim 1 to 3, it is characterized in that, described Sine Driving Mechanism comprises a sine arm, one end and the described rotation axis of described sine arm are in transmission connection, the other end of described sine arm and a sine mechanism jacking block are in transmission connection, and the output shaft of described sine mechanism jacking block and a stepper motor is in transmission connection.

5. parallel double grating monochromator according to claim 4, is characterized in that, described sine mechanism jacking block selects cam, and described cam is set on the output shaft of described stepper motor.

6. parallel double grating monochromator according to claim 5, it is characterized in that, described double grating monochromator also comprises the first entrance slit and first exit slit of corresponding described first grating, and the second entrance slit of corresponding described second grating and the second exit slit.

7. parallel double grating monochromator according to claim 1, is characterized in that, described framework is rectangular frame, and described first grating and described second grating are arranged along the length direction of described framework is parallel, and described rotation axis is arranged along the Width of described framework.