High Speed Wavelength Switcher Lambda DG-4 Plus / DG-5 Plus

A complete illumination system with speed and adaptability for experiments needing quick wavelength switching is the Lambda DG-4/DG-5 Plus. Faster filter switching and 30% more light output than the first version DG-4/DG-5 are now possible thanks to new digital servo technology. The instrument keeps all the benefits of interference filter-based systems while getting rid of the time restrictions associated with conventional filter-changing tools like filter wheels. Real-time video imaging is possible thanks to the quick 0.5msec switching between any two frequencies. The Lambda DG-4/DG-5 Plus's quick switching speed makes it possible to track rapid changes in ion concentrations in dual wavelength ratio imaging applications and to keep an eye on other concurrent changes in the system under study at other wavelengths.

Narrow bandpass devices let unwanted harmonics of the desired wavelength pass, such as single cavity interference filters, grating monochromators, and A.O. modulators. Additionally, it is not always feasible to achieve adequate blocking of out-of-band wavelengths with variable wavelength devices. Modern interference filters, like those found in the Lambda DG-4/DG-5 Plus, don't pass harmonics and have integral blocking properties that are 1000 times superior than those of conventional monochromator systems. Due to the lack of the slit function, interference filters have a narrower spectral bandpass for a given full width at half maximum (FWHM).

The Lambda DG-4/DG-5 Plus's dual galvanometer architecture enables tuning of the respective intensities at each wavelength. It is challenging to achieve this correction in variable wavelength devices with a singular optical path. When necessary, the Lambda DG-4/DG-5 Plus can be used as a source of white light, unlike monochromators and other wavelength selective devices.

How it works:

The Lambda DG-4/DG-5 Plus's distinctive optical design is based on dual scanning galvanometers that use interference filters to pick wavelengths. The first galvanometer mirror receives the light from the xenon arc lamp, which sends it through one of the interference filter channels via a parabolic mirror. The light is then collected and directed into the light path by a second parabolic mirror and a second galvanometer mirror after the filter. The IR radiation is eliminated by a cold mirror at the start of the light path, greatly decreasing the amount of heat absorbed by the optics and the sample. There are also cold mirrors that have been modified to transmit near-IR from 780 to 880nm.

A built-in shutter function enables a five to six order of magnitude decrease in light intensity. The SmartShutter® can be installed in the apparatus to ensure that the light is entirely blocked for uses that call for mechanical shuttering, such as time-lapse experiments or very sensitive samples. No longer is a distinct control device necessary thanks to a newly integrated SmartShutter controller.

Up to four 25 mm interference filters can be stored in the basic system, the Lambda DG-4 Plus. Three 18 mm and two 25 mm filters can fit inside the five filter Lambda DG-5 Plus. While it takes less than 0.5 msec to switch between any two wavelengths, the dwell duration at any wavelength is completely up to the user.

The illumination port of the majority of microscopes can be connected to the liquid light guide using an adapter, which can be bought independently. For more details, please see the Microscope Adapters section. With different cold mirror and light guide configurations, increased output ranges are feasible. To explore your unique application requirements, call Sutter.

FEATURES

• USB support
• Built-in SmartShutter® control
• Expanded menu options and enhanced triggering
• Integral shuttering
• Integral neutral density filtering
• Two outputs for monitoring filter position
• Turbo Blanking
• Direct computer control via parallel, serial, or USB interface
• Switches in 0.5 msec

COMMON APPLICATIONS

• Fluorescent microscopy
• Calcium imaging
• FURA
• Optogenetics
• Ultra high speed wavelength selection