Two Diffraction Gratings

UV-VIS CS260 monochromators come with two ruled gratings that are installed and aligned on a grating mount. A high precision motor is used to select the desired wavelength and switch between diffraction gratings quickly, without sacrificing performance.

Optical Design

The optical design of the Cornerstone 260 is based upon an asymmetrical in-plane version of a Czerny-Turner monochromator. The optical configuration is designed to ensure high resolution and maximum throughput. This f/3.9 monochromator is optimized to provide excellent stray light rejection while minimizing aberrations. A high precision motor is used to select the desired wavelength and switch between diffraction gratings quickly, without sacrificing performance.

Fixed Slit Versions

Fixed slits should be used for the utmost accuracy and repeatability, especially at high resolution. Fixed slits are the best option when only a few slit sizes are required, as they are less expensive. The fixed slits slide into the holder at the input port, as well as the holder at the lateral output port on dual output models. The width and height cannot be adjusted, but may be individually replaced with other slit sizes. Individual fixed slits are required and sold separately to allow customized choices based on the needs of the application (see accessory section). Order one fixed slit for single output port models, and two identical fixed slits for the dual output port monochromators. The slit width is one of the factors determining the resolution and throughput of the instrument, with a narrow slit providing higher resolution and lower throughput.

A fixed slit is shown installed into the fixed slit holder.

Micrometer Adjustable Slit Versions

Micrometer adjustable slits offer flexibility and high throughput, but are not as accurate or repeatable as fixed slits. The micrometer adjustable slit assembly is continuously variable from fully closed to 3 mm width. The narrowest practically achievable width is 4 µm. A height adjustment slide allows variation in the height from 2 to 12 mm. This type of slit is designed primarily for versatility and convenience in changing resolution and throughput.

Motorized Slit Versions

A motorized slit installed at the input port allows you to control the slit width of the input port through the include utility software, an optional hand controller, or the optional TracQ Basic software. This enables automated slit control or hands-off operation. The motorized slit assembly may be adjusted from 6 µm to 2 mm width in 6 µm steps. An advantage of using a motorized slit is that in addition to setting the slit width manually, the software can be configured with an automatic bandpass setting. The software adjusts the slit width to maintain the chosen bandpass as the wavelength range is changed. Manual calculation of the slit width for a desired resolution is valid at the peak wavelength for a grating. The software performs additional mathematical calculations to take into account any change in wavelength away from the blaze wavelength.

Optional Hand Controller

All models include a connector to utilize the optional 74009 Hand Controller for manual operation without a computer. There is no need to memorize commands or key sequences. The display provides information on the grating selection, active filter selected, current wavelength, shutter status, and more.

Motorized Filter Wheel Accessory Control

The CS260 is capable of automatically controlling the optional model USFW-100 filter wheel. These filter wheels hold up to six 1-inch diameter filters. Neutral density filters can be used for intensity adjustment. Order sorting filters may be installed to block higher order diffraction. The filter wheel can be mounted to the male flange of the monochromator slit or slit holder. The filters are mounted external to the monochromator.

Single or Dual Output Ports

The CS260 is available with a single output port or dual output ports. A single output port is the most economical choice, and the simplest arrangement when using a single detector. If more than one detector is required for the application, the use of a single output port instrument results in the experiment needing to be stopped to switch detectors. An alternative is to use a beamsplitter after the output port, which results in lower power reaching the two detectors. In this situation, a dual output port monochromator may be a better choice. Two output ports allow continuous scanning over a broad wavelength range without needing to break down the setup to swap detectors. A flip mirror inside the monochromator is used to select the output port. This mirror is controlled through the monochromator software, low level commands or the optional hand controller. Please note that with dual output port instruments, an unused port left uncoupled can become a source of stray light entering into the monochromator.

LabVIEW™ Utility Software Included

LabVIEW™ based utility software is included at no extra cost with all CS260 models to control both the monochromator and filter wheel accessory. An intuitive command set is provided for those wishing to create their own programming. The Oriel MonoTERM utility is also provided for sending low-level commands to the monochromator. This is very convenient for assisting programmers in their software development efforts. The MonoTERM utility was developed in National Instruments LabVIEW. It is open source code, so it may be used to provide LabVIEW™ programming examples.

USB or GPIB/RS232 Communication Interfaces

CS260 monochromators are offered with a USB or GPIB/RS232 communication interface. The utility software provided with the monochromator includes USB drivers for Windows 7 or 10, 32-bit and 64-bit operating systems. GPIB communication offers the distinct advantage of being able to connect multiple devices to a single GPIB port, provided the computer contains a GPIB adapter card. Both GPIB and RS232 communication methods simplify low-level communications, as there is no driver or dll file. USB versions include the USB cable. For RS232/GPIB monochromators, cable 70040(RS232) or 70038 (GPIB) may be ordered separately.

Built-In Shutter

An electronic shutter is integrated into the CS260 spectrograph's housing for the many spectroscopic applications that require the use of a shutter. For more information, please refer to the technical note entitled Shutters for Spectroscopic Applications.

Delivered Fully Assembled and Aligned

The CS260 is factory assembled and pre-aligned so it is ready for immediate use. The diffraction gratings are installed on a grating mount and factory aligned. A micrometer slit, motorized slit or fixed slit holder is installed to the input port and axial output port. Dual port versions include a slit or slit holder on the lateral output port. Also included with the CS260 is LabVIEW™ based utility software and API with examples. MonoTerm low-level command software, users manual and certificate of calibration. A DC power supply and line cords for US and Europe are also included.

Monochromator Mounting

The optional 74105 mounting plate can be used to secure a CS260 monochromator to an inch or metric optical table. The ability to mount the monochromator simplifies setup and alignment of the optical system. The mounting plate also helps ensure consistent results over time, as the monochromator cannot be accidentally moved out of position. The plate adds 0.25 inch [6.35 mm] to the optical height. Threaded holes on the mounting surface of the monochromator also allow the instrument to be optical rod mounted, if desired.

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 and communication electronics if desired. Learn more about our factory monochromator services.