Scientifica Multiphoton Detection Unit (MDU)

Maximise your photon collection when performing multiphoton fluorescence imaging.

The MDU is an optimised one or two-channel fluorescence collection and detection system specifically designed for multiphoton imaging with small back aperture objectives.

High sensitivity is achieved, as the MDU is available with up to two gated or protected GaAsP photon multiplier tubes (PMTs) and is optimised for integration with Scientifica’s SliceScope microscope.

The MDU has everything you need, comprising of pre-aligned optics, safety shutters/switches, a filter cube and either one or two PMTs. Each detection unit also contains a power supply, preamplifier and control unit.

Benefits

Optimum light collection

When used with a small back aperture, all scattered light is collected from the objective, maximising your image quality.

Photon collection at the widest of scan angles

Enabled by the customised optics, including a custom designed, extra-large fixed position collection lens sited very close to the objective back aperture.

Exceptional image quality

The high signal to noise ratio of the MDU means background noise is minimised, and image quality is enhanced, thanks to the superior electronic design of the MDU.

Ease of experimental setup

Fast filter exchange makes the setup of experiments simple. A standard Olympus filter cube is fitted to a dovetail slider which can easily move in and out of the MDU.

Increased photon capture

Maximised light collection from a wide range of objectives and condensers. Photons can be harvested from objectives that have either a small or large back apertures (RMS, M25, M27 and M32 thread adapters available).

Above or below the sample

Collect reflected fluorescence through the microscope objective, or transmitted fluorescence using a high-NA oil-immersion condenser lens. Alternatively, combine two MDUs simultaneously for optimum signal collection in up to four channels.

Achieve greater control

With gated GaAsP PMTs, you can have greater control when performing optogenetics experiments. This is because they enable the PMT to be desensitised for pulses of up to 10ms, whilst light stimulation is being applied. This not only optimises your experiments, but increases the lifetime of the PMT, by ensuring unreasonable levels of light are not damaging the amplification stages of the PMT.

Design & Specifications

Number of channels	Number of channels Two per MDU
Detector types	Detector types Bi- and multialkali PMTs, protected and gated GaAsP PMTs
Primary dichroic mirror	Primary dichroic mirror 665 nm long-pass dichroic
Laser blocking filter	Laser blocking filter 680 nm short-pass filter
Maximum objective exit aperture	Maximum objective exit aperture 24 mm diameter
Angular collection	Angular collection Collects 5° of divergent light
Objective compatibility	Objective compatibility Water-dipping M32X0.75, M27X0.75, M25X0.75 and RMS threaded types (direct or via adapters)
Spectral filtration	Spectral filtration One Olympus U-MF2 filter cube supplied (un-populated) compatible with standard fluorescence filter sets (25 mm filters and 24 x 36 mm dichroic mirrors, 1 mm thick)
Preamplifier bandwidth	Preamplifier bandwidth 1 MHz for galvo detection, 20 MHz for resonant detection. Variable preamplifiers available for fine tuning of bandwidth and gain
Preamplifier gain	Preamplifier gain 200,000 (galvo detection), 100,000 (resonant detection)
Output connection	Output connection SMA-BNC to the preamp and 3m BNC from preamp to DAQ
Inputs	Inputs BNC input for gate control on Gated GaAsP variant