|Monochromator-spectrograph MS750 series are devices with with a large flat focal field, combined with a high-intensity, accuracy and spectral resolution. They are completely automated spectral devices with focal length of 750 mm and F-number of 1/8.9, which can be used both as monochromators and spectrographs.
High-quality optics and wide choice of diffraction gratings provide devices operation in a wide range from 185 nm up to 60 µm (depending on the selected grating).
M750 Series monochromator-spectrographs are based on Cherny–Turner asymmetric scheme that allows to minimize of aberrations and exclude spectra re-entrance from diffraction gratings and mirrors.
Automated four-grating turret (model MS7504 and model MS7504i) provides a fast switching of gratings with high repeatability of the set wavelength and the vertical image.
In MS7501 and MS7501i models a single-position holder is used for easy manual switching of gratings.
A wide choice of changeable gratings gives the best combination of high energetic efficiency and maximal spectral resolution for different spectrum areas.
Monochromators–spectrographs of MS750 series have one input port and two output ports. Selection of an output port is realized with an automated mirror. Either output spectral slits or multi-channel detectors can be installed on each of the output ports.
Extremely high spectral resolution – better than 0.02 nm for grating 1200 grooves/mm,makeS monochromators-spectrographs of MS750 series ideal devices for high resolution spectroscopy: Raman spectroscopy, laser-induced breakdown spectroscopy and also for multi-channel spectroscopy – models MS7501i and MS7504i, which provides extremely high spatial resolution along the slit heigh.
I M A G I N G
Monochromator-spectrograph MS750 series, models
|Diffraction unit||Single-position holder for manually changeable gratings||Single-position holder for manually changeable gratings||Four–grating turret||Four–grating turret|
In the devices with the standard optics (model MS7501 and model MS7504) a flat entrance deflecting mirror is used, and in the astigmatism–compensated devices (model MS7501i and model MS7504i) a cylindrical mirror is used as an entrance deflecting.
As well as in all Czerny–Turner design spectral devices, in the MS750 series an axis of the diffraction gratings rotation goes through the center of grating operating surface and coincides with the direction of grooves. This fact provides the stability of the geometry of the beams for formation of a flat and fixed focal field. The image quality in the whole flat focal field is optimized due to the use of an asymmetric scheme and use of a focusing large-size mirror allows one to use the whole focal field width without vignetting. Besides, Cherny–Turner asymmetric scheme provides a low level stray light and light re-entrance from the optical elements and detectors can be avoided.
In MS7504 and MS7504i the gratings rotation axes are arranged perpendicular to the spectrum scanning axis, providing a high repeatability of wavelength setting at replacing of gratings.
(astigmatism–compensated in model MS7501i and model MS7504i)
|Ports:||1 input, 2 output|
|Wavelength range:||185 nm – 60 µm (depends on the type of grating)|
|Focal length (output):||750 mm|
|Scanning range limited by the grating rotation angle:||0 – 1270 nm (grating 1200 l/mm)|
|Stray light:||5.5 х 10-7 (20 nm from laser line 632.8 nm)|
|Focal plane:||28 х 10 mm|
Optical scheme is optimized for:
- minimization of coma aberration over the whole operating spectral range
- elimination of the light re-entrance from two basic mirrors
- elimination of the light re-entrance between mirrors
of the instrument and input windows of the detectors in the focal plane
- a large plane focal field for the whole operating spectral range
- astigmatism compensation for the whole operating spectral range
by means of special correcting optics (for imaging modifications MS7504i and MS7501i)
|*Vertical spatial resolution:||<15 m=”” –15–=””>|
* Characteristics of models with astigmatism compensation: MS7501i, MS7504i
Spectral images obtained with imaging monochromator-spectrograph MS7504i (grating 1800 l/mm,
light source – mercury-helium lamp, pixel size of CCD detector 24×24 µm).
|Step size:||0.22 arc seconds|
|Precision:||± 1 step|
|Max. speed:||10000 steps/s|
|Type of grating:||1200 l/mm,
λ = 546 nm
|Echelle, 75 l/mm,
λ = 200 nm, 120 order
|Reciprocal linear dispersion:||1.02 nm/mm||0.055 nm/mm|
|– PMT (slit width 10 µm):||0.015 nm||0.0008 nm|
|– digital cameras (12 µm pixel):||0.02 nm||0.0011 nm|
|Repeatability:||± 0.007 nm||± 0.0009 nm|
|Wavelength accuracy:||± 0.034 nm||± 0.0045 nm|
|Average scanning step:||0.0017 nm||–|
|Scanning step at 200 nm:||–||2.25 x 10-4 nm|
** For grating 1200 l/mm, slit width 15 µm, wavelength 546 nm
|Size:||80 х 70 х 10 mm|
|Rotation:||About the center of grating working surface|
|Mounting:||1. Automated 4-grating turret (models MS7504, MS7504i)
2. Positioner for 1 manually changeable grating (модели MS7501 и MS7501i)
|Grating repeatability for the automated 4-grating turret
(models MS7504, MS7504i):
|– wavelength:||± 0.03 nm|
|– vertical image:||± 50 µm|
|Grating repeatability for 1 manually changeable grating (models MS7501 and MS7501i):|
|– wavelength:||± 0.05 nm|
|– vertical image:||± 75 µm|
|Number:||1 input, 2 output|
|Output port repeatability (automated mirror):||± 0.01 nm|
|Switching time (output port):||10 s|
|Control:||Automated (drive) or manual (micrometer)|
|Width:||Regulated from 0 up to 2.0 mm|
|Parallelism:||± 1 µm|
|Accuracy (slit 1 mm):||± 10 µm|
|Repeatability:||± 1 µm (± 1.5 µm – manual slit)|
|Reading accuracy (micrometer):||2 µm|
|Step size:||0.5 µm|
|Height:||Diaphragm-regulated from 0 up to 10 mm|
|Shut time:||~ 100 ms|
|Max. frequency:||1 Hz|
|Control:||On-board CPU or TTL-signals from the external device|
|Overall sizes (LхWхH):||950 х 361 х 343 mm|
|Weight:||45 kg (may vary, depends on configuration)|
|MS750 Series monochromators-spectrographs are spectral devices with big focus length, which posses a wide range of different configurations for realization of spectral tasks which requires an extra-high spectral resolution and precision.
We offer several configurations, a wide choice of diffraction gratings, a great number of accessories and two types of the software.
You have a possibility to choose a necessary device configuration depending on your task to be solved from the given below list or consult our specialists
You can choose:
With interference optics for all options of the housing, on request
MS750 series monochromators–spectrographs are available with two types of diffraction grating mounting:
Single grating holder
The devices of this series have one input port on which an entrance spectral slit is installed.
There are two types of slits:
All spectral slits have standard coupling flanges providing direct attachment of various accessories of own production to the entrance slit: optical fiber adapter, condenser F#-matcher, filter wheel, fast shutters, etc.
MS750 Series devices have an integrated shutter. It is used for measuring of the background signal or dark signal of photodetector and also for protection of the detectors from high light intensities – the shutter is automatically shut while switching the gratings, filters, zero-order wavelength setting or change of the output port. The shutter can be controlled through software or via the external device TTL-signals.
Monochromators-spectrographs of MS750 Series have two types of input and output spectral slits:
Manually operated spectral slits
The slit width is operated manually by means of the micrometer. Slit height is regulated by a diaphragm in the range from o to 10 mm.
Automated spectral slits
In the automated spectral slits a stepper motor is used for PC control over the blades opening width. The slit width also may be controlled manually by means of a micrometer screw. The slit height is regulated by a special diaphragm.
All spectral slits have standard flanges that make possible attachment of various accessories of own production directly to the entrance slit: optical fiber adapter, condenser F#-matcher, filter wheel, fast shutter, detectors based on photodiodes, PMT, etc.
Monochromators-spectrographs of MS750 Series are completely automated spectral devices.
The basic control of the devices is executed through the embedded controller. It performs continuing control of commands execution from the external control device.
esides, the embedded controller takes control over the built-in ADC which processes signals from the integral photodetectors–PMT, photodiode and etc.
External control of the devices can is performed through PC.
The software DevCtrl is supplied with the device.
DevCtrl controls over all drivers and units of the device and accessories. The software also gives an access to the system parameters and setup coefficients of the device.
Spectroscopy software SpectraSP
Spectroscopy software SpectraSP is intended for joint control over monochromators–spectrographs and detection systems based on the integral or multi-element photodetectors. SpectraSP provides simultaneous control over the device and optical radiation detection by means of various detectors with subsequent data processing and their graphical displaying.
|While choosing a device configuration it is important to select properly the diffraction gratings. A right selection of the diffraction grating allows one to obtain the best combination of high energetic efficiency and spectral resolution.
The basic grating parameters which determine their right choice you can find in the methodical material “Spectral Instrument. Basic Concepts and Characteristics.”
We propose a wide range of diffraction gratings to be used in the MS750Series. Please, choose a necessary grating from the given below list, or consult our specialists.
Basic parameters for correct selection of diffraction gratings:
In the Table “Selection of diffraction gratings” groove density and blaze wavelength belong to a diffraction grating parameters. Other parameters characterize a spectral device together with a selected grating.
- Groove density. The diffraction grating has a periodic structure. Such parameters as resolving power and free spectral range are determined by the periodic structure properties of a diffraction grating. The period of grating is the distance through which grooves are repeated. The reciprocal value of a grating period is called the groove density and displays the number of grooves in 1 mm.
- Blaze wavelength. The reflectivity of a grating depends on the grooves geometry, because the direction to the center of the diffraction maximum is determined by the mirror reflection of the incident beam from the edge of a groove. In spite of rather flat profile of diffraction maximum a blaze wavelength that corresponds to the maximum efficiency of the grating has been adopted as a feature for convenience of calculation.
When selecting a grating it is useful to determine a blaze wavelength for a required grating on the spectral range of limited wavelengths WL1 and WL2. The blaze wavelength is determined by the ratio:
WLBlaze = 2 ∙ WL1 ∙ WL2 / (WL1 + WL2).
- Reciprocal linear dispersion. The light from a grating in the focal plane of a spectral instrument forms a spectrum. Linear dispersion is used for a spectrum characteristic, which is defined as a reciprocal value of the product of angular dispersion of a grating and focal length of a spectral instrument and shows the spectral range that falls on a single linear distance in a focal plane.
- The spectral resolution. Limiting resolution of a spectral instrument is equal to the minimum half-width of its instrument function. The instrument function is determined by finite sizes of entrance diaphragm, aberrations and also distortions caused by inaccuracy in manufacturing and adjustment of optical elements of instrument. In addition, instrument function, and thus spectral resolution are dependent on lighting method of entrance slit, used aperture and registration system parameters.
- Operating wavelength range. Energy efficiency range referred to the wavelength region in which grating reflection coefficient is not less than 0.405 of the maximum. In the first order this range is limited by the wavelengths: ⅔ ∙ WLBlazeand 2 ∙ WLBlaze.
Operating range usually corresponds to a grating energy efficiency. In some cases, for gratings with a high groove density and large blaze wavelength, the long-wave border of operating spectral range of instrument is limited by a maximal rotation angle of a grating which is defined by design of instrument.
Table for selection of diffraction gratings
|Blaze wavelength, nm||*Reciprocal linear dispersion, nm/mm||Spectral resolution,
|Operating wavelengths range, nm||Spectral range limited by the grating rotation angle, nm|
(wavelength 200 nm,
(wavelength 200 nm,
|783600||3600||hol||0.33**||0.0064||185 – 450||500|
|782422||2400||225||0.52||0.01||185 – 450||750|
|782427||2400||270||0.51||0.01||185 – 540||750|
|782770||2400||400||0.47||0.009||270 – 750||750|
|781827||1800||270||0.7||0.014||185 – 540||1000|
|781840||1800||400||0.67||0.013||270 – 800||1000|
|781840||1800||500||0.63||0.012||335 – 1000||1000|
|781875||1800||750||0.51||0.01||500 – 1800||1000|
|781225||1200||250||1.08||0.021||185 – 500||1500|
|781228||1200||280||1.07||0.021||190 – 560||1500|
|781240||1200||400||1.05||0.021||270 – 800||1500|
|781250||1200||500||1.03||0.02||335 – 1000||1500|
|781260||1200||600||1||0.02||400 – 1200||1500|
|781275||1200||750||0.95||0.019||500 – 1500||1500|
|780623||600||230||2.19||0.043||185 – 460||3000|
|780630||600||300||2.18||0.043||200 – 600||3000|
|780640||600||400||2.17||0.043||270 – 800||3000|
|780650||600||500||2.16||0.042||335 – 1000||3000|
|780660||600||600||2.14||0.042||400 – 1200||3000|
|780675||600||750||2.11||0.042||500 – 1500||3000|
|7804008||400||800||3.23||0.06||535 – 1600||4500|
|7804012||400||1200||3.16||0.06||800 – 2400||4500|
|7804017||400||1700||3.03||0.06||1135 – 3400||4500|
|7804020||400||2000||2.94||0.06||1335 – 4000||4500|
|7804025||400||2500||2.75||0.06||1670 – 4500||4500|
|780330||300||300||4.39||0.09||200 – 600||6000|
|780335||300||350||4.39||0.09||235 – 700||6000|
|780350||300||500||4.38||0.09||335 – 1000||6000|
|780360||300||600||4.37||0.09||400 – 1200||6000|
|780370||300||700||4.35||0.09||470 – 1400||6000|
|7803010||300||1000||4.31||0.08||670 – 2000||6000|
|7803015||300||1500||4.23||0.08||1000 – 3000||6000|
|7803020||300||2000||4.11||0.08||1335 – 4000||6000|
|7803030||300||3000||3.8||0.08||2000 – 6000||6000|
|7803035||300||3500||3.59||0.08||2330 – 7000||6000|
|780235||200||350||6.6||0.13||235 – 700||9000|
|780240||200||400||6.6||0.13||270 – 800||9000|
|780250||200||500||6.6||0.13||335 – 1000||9000|
|780270||200||700||6.6||0.13||470 – 1400||9000|
|7802015||200||1500||6.5||0.13||1000 – 3000||9000|
|7802020||200||2000||6.4||0.13||1335 – 4000||9000|
|7802025||200||2500||6.3||0.13||1670 – 5000||9000|
|7802030||200||3000||6.2||0.12||2000 – 6000||9000|
|781547||150||475||8.8||0.17||320 – 950||12000|
|781570||150||700||8.8||0.17||470 – 1400||12000|
|7815030||150||3000||8.5||0.17||2000 – 6000||12000|
|7815045||150||4500||8.1||0.16||3000 – 9000||12000|
|780165||100||650||13.2||0.26||435 – 1300||18000|
|780170||100||700||13.2||0.26||470 – 1400||18000|
|7801010||100||1000||13.2||0.26||670 – 2000||18000|
|7801020||100||2000||13.1||0.26||1335 – 4000||18000|
|7801025||100||2500||13||0.26||1670 – 5000||18000|
|7801030||100||3000||12.9||0.26||2000 – 6000||18000|
|7801042||100||4200||12.7||0.25||2800 – 8400||18000|
|7801048||100||4800||12.6||0.25||3230 – 9600||18000|
|7801055||100||5500||12.5||0.25||3670 – 11000||18000|
|7801062||100||6200||12.3||0.24||4130 – 12400||18000|
|7801072||100||7200||12||0.24||4800 – 14400||18000|
|7801088||100||8750||11.5||0.23||5830 – 17500||18000|
|7801097||100||9700||11.1||0.22||6470 – 18000||18000|
|7801103||100||10300||10.9||0.21||6870 – 18000||18000|
|7875070||75||7000||16.7||0.33||4670 – 14000||24000|
|7875095||75||9500||16||0.32||6330 – 19000||24000|
|7850010||50||1000||26.4||0.52||670 – 2000||36000|
|7850038||50||3800||26.2||0.52||2530 – 7600||36000|
|7850063||50||6300||25.8||0.51||4200 – 12600||36000|
|7850070||50||7000||25.7||0.51||4670 – 14000||36000|
|7850083||50||8300||25.5||0.5||5530 – 16600||36000|
|7850124||50||12400||24.6||0.48||8240 – 24820||36000|
|7850169||50||16900||23.2||0.46||11270 – 33800||36000|
|7850200||50||20000||22||0.43||13330 – 36000||36000|
|7837028||37.5||2800||35.1||0.69||18700 – 5600||48000|
|7837056||37.5||5600||34.8||0.69||3735 – 11200||48000|
|7837093||37.5||9300||34.3||0.68||6200 – 18600||48000|
|7837156||37.5||15600||33||0.65||10400 – 31200||48000|
|7824116||24||11600||54||1.1||7730 – 23200||75000|
|7824144||24||14400||53.6||1.1||9600 – 28800||75000|
|7824173||24||17300||53.1||1.1||11530 – 34600||75000|
|7824243||24||24300||51.6||1||16200 – 48600||75000|
|7824285||24||28500||50.5||1||19000 – 57000||75000|
|7824325||24||32500||49.2||1||21670 – 65000||75000|
* at the blaze wavelength
** at the wavelength 255 nm
For blaze wavelength 2000 nm and shorter the data measured by multielement detectors with entrance slit 15 microns.
For the wavelength more than 2000 nm the data obtained by calculation with the entrance slit 15 microns.