Features

Czerny-Turner Optical Design

The MS257 design is based on an asymmetric in-plane Czerny-Turner configuration. This off-axis design eliminates stray light caused by reflections from a detector window or optics internal to the instrument. This is critical to achieving high performance, as stray light could potentially be re-diffracted and affect the spectral purity of the output. The reflectors inside the MS257 are coated with AlMgF2 to maximize UV reflectance. Gold-coated reflectors for enhanced IR reflectance, are also available. Contact a Newport sales engineer for more information if these are required.

Grating Configurations Enable 200 nm to 20 µm Scans

Newport's patented quadruple grating turret assembly holds four gratings. Our wide selection of grating configurations enable this one instrument to perform extended wavelength range scans beginning in the ultraviolet (UV), and extending into the visible and near-infrared (NIR) wavelength regions. Users can choose from a variety of options that meets the wavelength scanning range and/or resolution requirements of his/her application. Custom grating requirements such as gold or AlMgF2 coatings are also available upon request. A wide offering of MS257 models are available based on grating selection, micrometer driven or motorized slit assembly, and single (axial) or dual output port access. For more information on the advantages of each option, see below. For a full listing of each model number, click here.  Please contact your Newport Sales Engineer for assistance in selection or purchasing a specific model.

Dual Output Port Accessibility Option

When configuring the MS257 to specific needs, a single output port (axial) or access to both axial and lateral ports can be chosen. The axial output port is in the internal optics' light output path and therefore provides greater throughput. The lateral output port's position on the MS257 provides better flexibility for mounting a detector or other external component due to its accessibility. Choosing the dual output port option allows two detectors to simultaneously be mounted to the MS257 for extended wavelength range scans. A motorized output mirror with a precise, highly repeatable mirror position will direct the light to the user requested output port at the command of Newport software, low level commands, or the 77709 hand controller. Redirection of light to the desired output port can be selected at any time, or pre-programmed at specific wavelength ranges. Newport also offers the 77765 motorized beam steerer. When coupled to the input port of the MS257 the 77765 allows two different light sources to be utilized with the instrument. For example, a deuterium light source and quartz tungsten halogen (QTH) light source can be coupled to the monochromator for extended range UV to IR light input.

Controls Up to Two Filter Wheels

The MS257 controls up to two optional filter wheels, model 77737 . Each filter wheel holds up to five 1-inch [25.4 mm] diameter filters, with a 0.92-inch [23 mm] clear aperture. Wavelength changeover points can be loaded into MS257 so the appropriate filter is automatically selected for any wavelength. This is of particular importance during a broad spectral scan, to block multiple orders and residual stray light. Newport’s Colored-Glass Alternative Filters are an excellent choice when selecting order-sorting filters. The filter wheels are externally mounted to the MS257.

Various Control Options including RS-232, USB, and Hand Controller

The MS257 offers users a variety of control options:

·USB and RS-232/GPIB (IEEE-448): The MS257 is equipped with both a USB and RS-232 port. For GPIB (IEEE-488) communication, the 77793 RS-232 to GPIB (IEEE-4878) External Interface is required.

·MS257 Utility Software: This utility program, included with the MS257 is written in National Instruments™ LabVIEW software. The program can be expanded upon to form a unique application software through use of the LabVIEW source code and VI's or .dll. Please note direct communication through the .dll is only available via USB 2.0 and not RS-232/GPIB (IEEE-488)

·TRACQ-BASIC Data Acquisition and Spectroscopy Software: This software application controls the MS257 as well as a variety of detectors to perform radiometric measurements. Data is graphed in real time and easily exportable for further analysis. 

·77709 Hand Controller: This controller is a good option for those who do not wish to use a computer due to convenience or security concerns. It provides access to almost all of the MS257's functionality including grating selection, active filter position, current wavelength, shutter status and more.

·TTL signal as well as auxiliary input and output connectors are located on the back panel of the MS257. The TTL signal enables control of select functions such as the integrated shutter and output port mirror, for dual output port models.

Integrated Shutter

A solenoid driven shutter is integrated into the MS257. This shutter automatically closes when changing gratings and filters in order to protect the detector from possible high light intensities at various grating angles - particularly the zero order white light. The shutter can be closed for dark scans and dark current measurements at the command of the included MS257 utility software, TracQ™ Basic Data Acquisition and Radiometry Software, low level command, 74009 hand controller, or external TTL signal.

Controls Up to Two Filter Wheels

The MS257 can control up to two filter wheels, model 77737 or USFW-100 (sold seperately). The filter wheel can be controlled manually via commands from the MS257, or pre-programmed to rotate to a particular filter wheel position at specific wavelength ranges. This is useful during broad spectral scanning applications, where blocking multiple orders of light and residual stray light is important.

Double Monochromator Configuration for Additive Dispersion Available

Two MS257 monochromators, configured with identical gratings and three slit assemblies, can be mechanically coupled via a light tight connection and mounted to a single baseplate to hold the proper optical alignment. Dual monochromator configurations are only controllable via RS-232. An additive double monochromator configuration uses the second monochromator to provide a second level of dispersion from the output light of the first monochromator. The result is linear light dispersion approximately double that of a single monochromator (ignoring all aberrations), and slightly better resolution. Contact a Newport Sales Engineer for assistance in configuring a double monochromator system.

Double Monochromator Configuration for Subtractive Dispersion Available

Two MS257 monochromators, configured with identical gratings and three slit assemblies, can be mechanically coupled via a light tight connection and mounted to a single baseplate to hold the proper optical alignment. Dual monochromator configurations are only controllable via RS-232. A subtractive double monochromator configuration uses the second monochromator to recombine the output light of the first monochromator. The result is almost zero linear light dispersion at the output of the second monochromator. This uniformity in wavelength between the left and right edges of the output slits is useful for applications such as spectral responsivity characterization of a detector. Contact a Newport Sales Engineer for assistance in configuring a double monochromator system.

Mounting Plate Accessory

The optional 77775 mounting plate can be used to secure the MS257 to an Imperial or metric optical table. Using the 77775 allows simplifies setup and optical alignment of the MS257 with other components, and prevents these components from being accidentally moved out of position.

Long Life Instrument

These instruments continue to function for many years. With proper care, they only require periodic maintenance to ensure gears are lubricated, spring tension is correct, etc. It is suggested to send the instrument to Newport annually for recalibration, in order to meet its performance specifications. During recalibration, the instrument is thoroughly examined and routine maintenance services are performed. In addition to this service, Newport is also able to reconfigure the grating selection, slits, shutter and output mirrors if desired. Contact Newport Sales for more information.