Lambert Instruments

The II18MD is an Image Intensifier with an 18mm diameter input screen that can be Modulated in the range of 1-120 MHz and is Digitally controlled. The II18MD modulated image intensifier is used as key component for FLIM -Fluorescence Lifetime Imaging Microscopy in the frequency domain. However, another interesting application is Diffuse Optical Tomography (DOT), e.g. for three-dimensional in vivo imaging of human breast tumor to distinguish benign and malignant lesions.
See the Wikipedia pages for more information:

• Optical coherence tomography (OCT) is an optical signal acquisition and processing method allowing extremely high-quality, micrometer-resolution, three-dimensional images from within optical scattering media (e.g., biological tissue) to be obtained.
• Diffusive optical imaging is a technique that gives cognitive neuroscientists the ability to simultaneously obtain information about the source of neural activity as well as its time course. In other words, it allows them to "see" neural activity and study the functioning of the brain.

Components
The II18MD modulated image intensifier is provided with a control unit containing the high voltage power supply and RF (Radio Frequency) amplifier. The control unit has a low voltage input to receive the external modulation signal that has to be amplified and biased with a variable DC photocathode voltage. Adjusting the MCP voltage controls the image intensifier gain. To prevent damaging, the image intensifier has an overload protection circuit that switches off the image intensifier when the light output becomes too high.

Depending on the application, the photocathode has to be chosen that has the appropriate sensitivity per emission wavelength. For GenII we normally offer either the S20 or the SuperS25 photocathode. For higher quantum efficiency (25% instead of 10%) the GenIII intensifier is offered, with the GaAs photocathode. See here for the photocathode characteristics.

The II18MD modulated image intensifier has an integrated high quality relay lens for optical coupling to a 1/2” or 2/3” CCD camera.