Sutter Instrument has developed several filter changers specially designed for wavelength selection over a wide spectral range to any given nanometer value.
The Lambda VF-5™, Lambda VF-10, Lambda VF-1™ and Lambda VF-1 Edge™ employ the innovative VersaChrome® and VersaChrome Edge™ thin-film filter technology from Semrock® to provide outstanding bandpass characteristics such as high transmission (close to 100%), steep edges and out of band blocking.
These tunable filter systems produce the center wavelength you select on command. And since these filters pass an image, they are equally suitable for emission and excitation paths.
How It Works
A specific wavelength within the wide spectral range of each filter is obtained by adjusting the angle of incidence from 0 to 60 degrees.
This tuning causes little or no change in spectral performance of the filter regardless of the state of polarization of the light passing through the filter.
The current VersaChrome series has 15 filters covering 338 to 900nm. By simply selecting the desired center-wavelength on the controller, users can select any combination of filters for the Lambda VF-5 (which holds up to 5 filters), any single filter in the series for the Lambda VF-1 or any one of 10 filters in the VF-10 that uses smaller filters suitable for laser applications.
The latest development from Semrock is the VersaChrome Edge filter technology that allows selection of the band-width as well as the center wavelength.
This new filter system uses separate tunable high-pass and low -pass filters in series to define the bandpass. An additional filter is used in series with these filters to provide the best blocking outside the pass-band.
The controller for these new tunable filter changers is a special version of our Lambda 10-B. Users can select the desired center wavelength in 1nm increments from the keypad, or via the serial or USB ports.
This allows control of the Lambda VF instruments with minimal changes to existing software supporting the popular Lambda 10-B controller. A sequence of wavelengths can be stored in the controller and the TTL input can then be used to trigger selection of the wavelengths in the sequence step-to-step. The firmware includes filter-specific data for each of the VersaChrome filters in the series.
The Lambda VF-1 Edge
To take advantage of the new VersaChrome Edge filters, Sutter has introduced the Lambda VF-1 Edge system that allows user selection of the both the long and short end of the bandpass in nanometer steps.
This new device incorporates two of our VF-1 filter tilting modules and a Sutter Lambda 10-B controller to give direct control over the bandpass via the unit’s keypad or through external control from a computer or other device.
Individual VF-1 modules can also be used with the VersaChrome Edge filters to provide tunable high-pass or short pass filtering.
The filter sets available for the VF-1 Edge cover the wavelengths from <400nm to more than 1100nm. Within this range you can select the half-power point for the high-pass and low-pass filters to any value in steps of 1 nm.
If the low pass wavelength is set higher than the high pass wavelength the transmission will be blocked, acting as a shutter. In the case of this filter set there are more than 5,000 combinations of filter settings available.
The Lambda VF-5
Along with the ability to select any wavelength in the range covered by any combination of 5 VersaChrome filters, the Lambda VF-5 has a patented white-light output mode that allows the user to access the full spectral output of the excitation light source when it is required.
White-light output is achieved by capturing the rejected light from the VersaChrome filter at a 45 degree angle and then combining the two beams on the output side of the VF-5. If this configuration is desired, it requires an additional custom light guide and SmartShutter® system.
When using the Lambda VF-5 for emission applications, we suggest installation of the 5 filters with the longer center-wavelengths covering from 430nm to 800nm. For excitation applications, we suggest installing the 5 filters with the shortest wavelengths covering 338 to 620nm.
For special applications, any combination of 5 filters could be installed in the Lambda VF-5. The compact Lambda VF-1 accepts any single filter in the series. The single VersaChrome filter installed in the Lambda VF-1 can be changed as needed.
The Lambda VF-1
The Lambda VF-1 accepts any single filter in the series, which can be exchanged with other filters as needed. This model offers faster switching times as well as a more compact and affordable system.
When used with the Lambda VF-1, the controller is able to also control a separate filter wheel or SmartShutter.
Features
- NEW: Now supported by the Lambda 10-3 with special programming
- NEW: Patented white light output capability
- Wavelength range as wide as 338-900nm
- Access any center-wavelength in nanometer increments
- Images pass through filters making it suitable for both excitation and emission
- Easily switch between fluorphore combinations
- Optional liquid light guide offers absolute vibration isolation
- All the advantages of thin-film technology - high transmission, steep spectral edges, high out-of-band blocking
- Polarization independence (s and p nearly identical)
Special Features – Lambda VF-1 EDGE
- Separate tunable high-pass and low-pass filters let user define the bandpass in nanometer steps
- User selectable band-width and center wavelength
- Blocking filter ensures best blocking outside bandpass
- Based on Semrock VersaChrome Edge technology
Applications
- Hyperspectral imaging
- Fluorescence imaging
- Ratiometric imaging