|MSDD1000 series Monochromator–spectrograph is a double dispersion monochromator-spectrograph with the effective focal length of 1 m. Double scheme combines a high spectral resolution which is peculiar to long-focus instruments, extremely low stray light being the advantage of double schemes and small sizes of single monochromators–spectrographs.
MSDD1000 series Monochromator–spectrograph is a completely automated spectral instrument with the effective focal length of 1000 mm (2х500 mm) and F\number of 1/5.9, which is applicable as a monochromator or a spectrograph with a large flat field.
The MSDD1000 series is designed on the modified Cherny-Turner scheme with the two-level arrangement of optical components to allow dispersion doubling, aberrations minimization and exclusion of spectra re-entrance from the diffraction gratings and mirrors.
This is a double dispersion monochromator with no intermediate slit, in which upper and lower levels are the separate monochromators. These two levels are connected by means of two plane turning mirrors.
High-quality optics and a wide choice of diffraction gratings provide operation of the MSDD1000 series monochromator-spectrograph in a wide spectral range from 185 nm up to 60 µm (depending on the selected grating) with the best spectral resolution.
In MSDD1002i model and MSDD1004i model the astigmatism is corrected owing to special optics what makes these instruments applicable in multi-channel spectroscopy. ONLY one input port is used in these instruments.
MSDD1000 series Monochromator–spectrograph has two input (only the models with no astigmatism compensation – MSDD1002 model and MSDD1004 model) ports and two output ports. Selection of the output ports is realized with flip mirrors. Either exit spectral slits or multi-channel detectors can be established in each of the output ports.
MSDD1000 series Monochromator–spectrograph has two types of entrance and exit spectral slits: manual, operated with a micrometer screw, and automated (combined) when the slit width is operated automatically or manually (with micrometer).
A wide choice of changeable gratings gives the best combination of high energetic efficiency and maximal spectral resolution for different spectrum areas.
We also propose a great choice of additional accessories for MSDD1000 series monochromator–spectrograph: filter wheel (6 and 8 filters), fast shutters with the opportunity of radiation direct delivery or via optical fiber, optical fibers with adapters, input and output condensers, integral and multi-element detectors and etc.
Extremely high spatial resolution (better than 0,004 nm for 3600l/mm grating) in combination with high throughput (F/number 1/5.9) make double dispersion monochromator–spectrographs of MSDD1000 series an ideal instrument for spectroscopy applications requiring high resolution in the limited area, when other instruments can not be physically applied.
I M A G I N G
Automated turret for two pairs of gratings (MSDD1004 model and MSDD1004i model) provides a fast switching of gratings with high repeatability of the set wavelength.
In MSDD1002 model and MSDD1002i model a fixed holder is used for easy manual switching of gratings.
|Models MSDD100 Series||MSDD1002||MSDD1002i||MSDD1004||MSDD1004i|
|Diffraction unit||Fixed holder for manually changeable gratings||Fixed holder for manually changeable gratings||Turret for two pairs of gratings||Turret for two pairs of gratings|
|Optics||Standard||Astigmatism–compensated (Imaging)||Standard||Astigmatism–compensated (Imaging)|
As well as in all Cherny–Turner scheme–based spectral instruments, in MSDD1000 series monochromator–spectrographs an 00′ axis of the diffraction gratings rotation goes through the center of grating operating surface and coincides with the direction of lines. This fact provides the stability of the geometry of the beams for formation of a plane and fixed flat field. In the instrument with an automated turret, gratings rotation axes M-M1 and N-N1 are arranged perpendicular to the spectrum scanning axis, providing a high repeatability of wavelength setting at replacing of gratings.
|Optical scheme:||modified Cherny–Turner two-fold configuration|
|Wavelengths range:||180 nm – 60 µm|
|Focal length:||1000 mm (2 х 500 mm)|
|Scanning range limited by the grating rotation angle:||0 – 1280 nm (grating 1200 l/mm)|
|Stray light:||10-8 (20 nm from laser line 632,8 nm)|
|Flat field:||28 х 10 mm|
|Vertical spatial resolution
Minimal distance between the edges of two neighboring tracks (in multi-channel spectroscopy):
|–||–||< 15 µm||< 15 µm|
Grating 1200 l/mm, light source – mercury-helium lamp: (576.961 nm and 579.067 nm), multi-channel optical fiber bundle,
fiber core diameter 200 µm, CCD pixel size 12×12 µm)
|Step size:||0.18 arc seconds|
|Precision:||± 1 step|
|Max. speed:||10000 steps/s|
Optic (for grating 1200 l/mm, wavelength 546 mm)
|Reciprocal dispersion:||0.82 nm/mm|
|Repeatability:||± 0.005 nm|
|– PMT:||0.013 nm|
|– digital cameras (12 µm pixel):||0.017 nm|
|Wavelength accuracy:||± 0.028 nm|
|Average scanning step:||0.0014 nm|
|Size:||80 х 70 х 10 mm|
|Rotation:||About the center of ruled grating surface|
|Mounting:||1. Automated turret for 2 pairs of gratings
2. Holder for 1 pair of manually changeable grating
|Automated turret for 2 pairs of gratings (MSDD1004 model and MSDD1004i model)
|– wavelength:||± 0.006 nm|
|– vertical image:||± 20 µm|
|Holder for 1 manually changeable grating (models MSDD1002 and MSDD1002i)
|– wavelength:||± 0.05 nm|
|– vertical image:||± 75 µm|
|Numbers:||2 input, 2 output|
|Output port repeatability (automated mirror):||± 0.01 nm|
|Switching time (input port):||4 s|
|Switching time (output port):||4 s|
Spectral slits automated (combined)
|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|
|Reading accuracy (micrometer):||2 µm|
|Step size:||0.5 µm|
|Height:||Diaphragm-regulated from 0 up to 10 mm|
Spectral slits (manually operated)
|Width:||Regulated from 0 up to 2.0 mm|
|Parallelism:||± 1 µm|
|Accuracy (slit 1 mm):||± 10 µm|
|Repeatability:||± 1.5 µm|
|Reading accuracy (micrometer):||2 µm|
|Height:||Diaphragm-regulated from 0 up to 10 mm|
|Number:||2 (in each input port)|
|Shut time:||~ 100 ms|
|Max. frequency:||1 Hz|
|Control:||On-board CPU or TTL-signals from the external device|
|Overall sizes (LхWхH):||556 х 324 х 340 mm|
|Weight:||35 kg (may differ, depends on configuration)|
|MSDD1000 series monochromator-spectrographs are double dispersion devices with a great variety of configurations for solving spectroscopytasks, which require a high resolution, low stray light and high precision. We propose several configurations of the device, a wide choice of diffraction gratings, great number of accessories and two types of the software.
You have a possibility to choose a necessary device configuration from the given below list depending on your task to be solved or consult our specialists.
You can choose:
Types of housing:
With interference optics, on request.
There are two embodiments of diffraction gratings mounting:
Automated turret for two-pairs diffraction gratings
The automated turret provides switching of gratings by pressing one button of the control PC software. Grating rotation axes in the turret are arranged perpendicular to the spectrum scanning axis allowing a high reproducibility of the set wavelength while the gratings are switched.
Holder for one pair of diffraction gratings
It provides easy manual switching of gratings. Gratings are positioned with high accuracy in holder and no additional alignment of the device is needed while the gratings are switched.
|Monochromators–spectrographs model MSDD1002 and model MSDD1004 posses two input ports operating in turn – axial and lateral. Astigmatism – compensated devices (modelMSDD1002i and model MSDD1004i) posses only one lateral port. Selection of the input port is realized by means of flip mirror.
The input port through which radiation is delivered to the device is active. On each of the input ports entrance spectral slit can be installed.
There are two types of slits:
All spectral slits have standard flanges, due to which various accessories (of own production) can be mounted directly to the entrance slit: optical fiber adapter, condenser F#-matcher, filter wheel, fast shutters, etc.
|MSDD1000 series can be supplied with the following configuration of input ports:
One axial input port
When only one input port is used it is preferably to choose a configuration with axial input port, as in this case no input flip mirror contributing slight losses due to the additional reflecting surface is required.
In the case of configuration with one axial port a lateral input port is covered with a cap.
One lateral input port
For some applications the lateral input port is required – for example, for monochromators cascading. For the one lateral input port configuration a fixed flip mirror is used.
One lateral port is used in the astigmatism – compensated monochromators – spectrographs (model MSDD1002i and model MSDD1004i).
Two input ports
When both output ports are used the automated input flip mirror is installed in the device for the fast and highly-precise ports switching. The input port through which radiation is delivered to the device is called active.
In MSDD1000 series a separate independent light shutter is used for each input port. Inactive input port shutter is automatically blocked, when the active port is selected. Shutters are used for measuring of the background signal or dark signal of photodetectors as well as for protection of photodetectors from high-intensity radiation. The shutter is automatically shut while zero-order wavelength is setting. The shutter is controlled with the control PC software as well as with TTL-signals of the external device.
There are two types of entrance and exit spectral slits:
Manually operated spectral slits
The slit width is operated manually with the micrometer screw. The slit height is regulated by a diaphragm in the range of 0 – 10 mm.
Automated spectral slits
In the automated spectral slits a stepper motor is used for control over the width of the blades opening either with PC or a hand controller. The slit width also may be controlled manually by means of a micrometer screw. The slit height is regulated by a diaphragm in the range of 0 – 10 mm.
All spectral slits have standard flanges which allow attachment of various accessories (of own production) directly to the entrance slit: optical fiber adapter, condenser F#-matcher, filter wheel, fast shutter, photodiode and PMT detectors, etc.
MSDD1000series monochromators – spectrographs are completely automated spectral devices.
The embedded controller is the basic control unit of the device that performs regular control of the operational commands from the external control device. Besides, the embedded controller takes control over the build-in ADC that process signals from the integral photodetectors – PMT, photodiodes,etc.
External control of the device is performed by PC.
Control software DevCtrl
Service software DevCtrl is supplied with the device.
DevCtrl program controls all drivers, units and accessories of the device. 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 MSDD1000 Series. 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.
MSDD1000 series Monochromator-spectrograph serves for obtaining high spectral resolution with small size of the device, thus there are certain limitations when choosing gratings, connected with a specific optical schematic of this type of the device.
The MSDD 1000 series – double dispersion monochromator-spectrographs with the two-level arrangement of optical components to allow dispersion doubling. In order to avoid downfall of two adjacent orders of the same decomposed in a spectrum wavelength from one grating to another, the spectral range of MSDD1000 series has limitations in a short-wave region for the gratings with low lines density.
|Minimal operating wavelength, nm|
There is no limitation in a short-wave region for gratings with high groove density.
Table of diffraction gratings
|Blaze wavelength, nm||*Reciprocal linear dispersion, nm/mm||Spectral resolution,
|Operating wavelength range, nm||Spectral range limited by the grating rotation angle, nm|
|783600||3600||hol||0.27**||0.0056||185 – 425||425|
|782422||2400||225||0.41||0.009||185 – 450||640|
|782427||2400||270||0.41||0.009||185 – 540||640|
|782770||2400||400||0.39||0.008||270 – 640||640|
|781827||1800||270||0.55||0.011||185 – 540||850|
|781840||1800||400||0.54||0.011||270 – 800||850|
|781840||1800||500||0.53||0.011||330 – 850||850|
|781875||1800||750||0.46||0.009||500 – 850||850|
|781225||1200||250||0.84||0.017||185 – 500||1280|
|781228||1200||280||0.84||0.017||190 – 560||1280|
|781240||1200||400||0.83||0.017||270 – 800||1280|
|781250||1200||500||0.82||0.017||335 – 1000||1280|
|781260||1200||600||0.81||0.017||400 – 1200||1280|
|781275||1200||750||0.79||0.016||500 – 1280||1280|
|780640||600||400||1.67||0.035||300 – 800||2560|
|780650||600||500||1.67||0.035||335 – 1000||2560|
|780660||600||600||1.67||0.035||400 – 1200||2560|
|780675||600||750||1.66||0.035||500 – 1500||2560|
|7804008||400||800||2.51||0.052||535 – 1600||3840|
|7804012||400||1200||2.49||0.052||800 – 2400||3840|
|7804017||400||1700||2.45||0.051||1135 – 3400||3840|
|7804020||400||2000||2.41||0.05||1335 – 3840||3840|
|7804025||400||2500||2.32||0.048||1670 – 3840||3840|
|780370||300||700||3.34||0.07||600 – 1400||5120|
|7803010||300||1000||3.34||0.07||670 – 2000||5120|
|7803015||300||1500||3.33||0.07||1000 – 3000||5120|
|7803020||300||2000||3.3||0.07||1335 – 4000||5120|
|7803030||300||3000||3.16||0.07||2000 – 5120||5120|
|7803035||300||3500||3.05||0.06||2330 – 5120||5120|
|7802015||200||1500||5||0.1||1000 – 3000||7680|
|7802020||200||2000||5||0.1||1335 – 4000||7680|
|7802025||200||2500||5||0.1||1670 – 5000||7680|
|7802030||200||3000||4.9||0.1||2000 – 6000||7680|
|7815030||150||3000||6.7||0.14||2000 – 6000||10240|
|7815045||150||4500||6.5||0.14||3000 – 9000||10240|
|7801025||100||2500||10||0.21||1800 – 5000||15360|
|7801030||100||3000||10||0.21||2000 – 6000||15360|
|7801042||100||4200||10||0.21||2770 – 8320||15360|
|7801048||100||4800||10||0.21||3230 – 9680||15360|
|7801055||100||5500||9.9||0.21||3670 – 11000||15360|
|7801062||100||6200||9.9||0.2||4130 – 12400||15360|
|7801072||100||7200||9.8||0.2||4800 – 14400||15360|
|7801088||100||8750||9.5||0.2||5830 – 15360||15360|
|7801097||100||9700||9.3||0.19||6470 – 15360||15360|
|7801103||100||10300||9.2||0.19||6870 – 15360||15360|
|7875070||75||7000||13.3||0.28||4670 – 14000||20480|
|7875095||75||9500||13||0.27||6330 – 19000||20480|
|7850038||50||3800||20||0.42||3600 – 7600||30720|
|7850063||50||6300||20||0.42||4200 – 12600||30720|
|7850070||50||7000||20||0.42||4670 – 14000||30720|
|7850083||50||8300||20||0.42||5530 – 16600||30720|
|7850124||50||12400||19.7||0.41||8270 – 24800||30720|
|7850169||50||16900||19.2||0.4||11270 – 30720||30720|
|7850200||50||20000||18.6||0.38||13330 – 30720||30720|
|7837093||37.5||9300||26.7||0.55||6200 – 18600||40960|
|7837156||37.5||15600||26.4||0.55||10400 – 31200||40960|
|7824116||24||11600||41.8||0.87||7730 – 23200||64000|
|7824144||24||14400||41.8||0.87||9600 – 28800||64000|
|7824173||24||17300||41.7||0.86||11530 – 34600||64000|
|7824243||24||24300||41.3||0.86||16200 – 48600||64000|
|7824285||24||28500||40.8||0.85||19000 – 57000||64000|
|7824325||24||32500||40.3||0.84||21670 – 64000||64000|
* 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.