Redefining Single-Photon Detection Technology
Photonis single-photon-detection solutions are based on vacuum-tube detector technology. This technology combines high detection efficiency (QE) with an extremely low amount of dark counts (dark noise). After pulsing, the phenomenon in which a detector generates a pulse after it already has detected a photon is minimal, and dead time is non-existent. Photonis’s patented high-end microchannel plate (MCP) technology offers a high dynamic range, an unmatched collection efficiency (CE), and excellent temporal characteristics.
Working principle of a vacuum tube detector
A vacuum tube photon detector is a type of detector that uses a vacuum tube to detect photons. It works on the principle of the photoelectric effect, which is the emission of electrons from a material as it absorbs electromagnetic radiation, such as light.
A vacuum tube is a sealed container that contains a vacuum. Inside the vacuum there is a cathode, an MCP, and an anode separated by a small gap. The cathode is a metal surface that emits electrons when it is struck by photons. The MCP multiplies the generated photoelectrons, and the anode is also a metal surface that collects the emitted electrons.
When photons strike the photocathode, they are absorbed by the metal surface, causing electrons to be emitted. These emitted photoelectrons are then accelerated towards the MCP by an applied voltage, which generates a current that is proportional to the number of detected photons. The vacuum inside the tube ensured that the electrons do not collide with any gas molecules, which could otherwise interfere with the detection process.
Single-photon counting using an MCP-PMT
Microchannel plate photomultiplier tubes (MCP-PMT)s are commonly used in high-end LIDAR applications and various fields, such as medical imaging, nuclear physics, and astronomy. In these fields of research, counting single photons is essential for accurate detection and measurement. Fast MCP-PMTs can detect very low levels of light and produce a high gain output signal, making them an ideal choice for detecting individual photons of light.
MCP-PMTs consist of a window with a photocathode, a stack of micro-channel plates (MCPs), and an anode.
In single photon counting applications, MCP-PMTs operate in the following way:
- A photon enters the MCP-PMT and interacts with the photocathode, causing the emission of an electron.
- The emitted electron is accelerated and multiplied as it passes through the stack of micro-channel plates (MCPs), which are essentially thin plates with many microscopic channels.
- The multiplied electrons are then collected by the anode, which produces an output signal that can be detected and analyzed.
MCP-PMTs are particularly suited to single-photon-counting applications because they have a very high quantum efficiency, which means they can convert a high percentage of incident photons into an electron signal. They also have a fast response time, can detect very low levels of light, and generate an extreme low number of dark counts.
Single-photon imaging using an image intensifier tube (IIT)
The use of Image Intensifier Tubes (IITs) in single-photon-imaging applications can greatly improve the sensitivity of the system, allowing for the detection and imaging of individual photons. In addition to their use in biological imaging, quantum imaging, and astronomy, IITs are also used in a variety of other applications, including night vision, military imaging, and industrial inspection.
The basic principle of single photon imaging using an IIT is as follows:
- A photon enters the IIT through the input window and strikes a photocathode, which is typically made of a material such as cesium or potassium.
- The photon causes the photocathode to emit electrons, which are then accelerated towards an MCP by an electric field.
- The electrons passing through the MCP cause a cascade of secondary electrons, resulting in a significant amplification of the electron signal.
- The amplified electron signal is then accelerated towards a phosphor screen, which emits visible light when struck by electrons.
- A sensitive camera, such as an EMCCD or sCMOS camera, is used to capture the light emitted by the phosphor screen and produce an image.
The Cricket™² contains an IIT, which is often used in single photon imaging applications to amplify the signal from individual photons and produce a measurable output signal. In single-photon imaging, the goal is to detect and image single photons, which can be very difficult due to the extremely low levels of light involved. IITs can help to overcome this challenge by providing a high gain amplification of the photon signal, making it possible to detect and image single photons.
Single-photon imaging and counting using a TPX3 chip
The Mantis3 combines the TPX3CAM with a Cricket™² thereby creating a single-photon-sensitive, state-of-the-art imaging system. The Mantis3 was specially developed for use in high-resolution imaging and spectroscopy applications and various quantum imaging applications, including single-photon detection, quantum key distribution, quantum entanglement, and quantum teleportation.
The Timepix3 chip used in the Mantis3 is a hybrid-pixel detector containing 256 x 256 pixels, a high time resolution of less than 1 nanosecond, and a high spatial resolution of 55 micrometers, which makes it ideal for quantum imaging applications. The Mantis3 also features a high-speed readout and can operate at high frame rates of up to 1,000 frames per second.
One of the key features of the Mantis3 is its ability to perform simultaneous energy and time-resolved imaging. This is achieved through the use of a Time-over-Threshold (ToT) technique, which allows the camera to measure the energy of each detected particle or photon as well as its time of arrival. This enables the Mantis3 to produce high-resolution images and spectra of a wide range of samples, including biological tissues, materials, and subatomic particles.
The Mantis3 is also highly configurable, which makes it ideal for use in a wide range of imaging applications. It can be configured to detect particles or photons in different energy ranges, and it can also be programmed to detect specific patterns of particles or photons that are associated with certain phenomena.
Overall, the TPX3CAM is a powerful imaging system that is specifically designed for quantum applications. Its high time and spatial resolution, high-speed readout, real-time data analysis capabilities, and configurability make it an ideal tool for a wide range of quantum imaging applications.
Click the link to learn more about Photonis’s single-photon counting and imaging technology.
To request more information or a quotation for Photonis products, contact IL Photonics.