> Photon Counting devices based on solid-state Single Photon Avalanche Photodiodes (SPAD)
Photon Counters
Micro Photon Devices offers a comprehensive family of Single Photon Avalanche Diodes (SPADs) ranging from Silicon Single Pixel to InGaAs detectors.
PDM
The PDM series photon counting detector modules are all solid-state instruments. They have a photon detection efficiency of 49% at 550nm and generate a TTL output pulse per detected photon. With fast-timing option (additional circuit board installed) they provide better than 50ps FWHM photon timing resolution.
The excellent photon detection efficiency and superior timing resolution is obtained through the use of epitaxial silicon Single Photon Avalanche Diodes (SPAD) and Active Quenching Circuits (AQC), specifically designed and optimized for photon counting applications.
Versions with optical Fiber Receptacle (PDF) to couple to all SingleMode and MultiMode fibers, up to 105um are available.
Main module features:
- 20µm, 50µm and 100µm active sensing area diameter
- Free Space an Fiber Receptacle versions available
- Available in different Grade depending on Dark Counts specifications
- Timing resolution lower than 50ps FWHM (optional)
- Detection efficiency up to 50% @ 550nm
- Uniform performances all-over the active area
- Peltier-cooled
- Fiber coupling efficiency greater than 80%
- Low power consumption
- Robust and low cost
- Easy to use
DATASHEET – PDM
USER MANUALS – PDM UserManual
APPLICATION NOTES – FiberCoupling a Window PDM
FastGatedSPAD
The PDC module is a singThe FastGatedSPAD module is a compact detection module capable of gating a silicon SPAD for wide dynamic range optical measurement. The module includes a fast pulse generator, with gating transitions below 300 ps at repetition rates up to 80 MHz, with fully programmable ON time and excess bias. The differential front-end electronics picks up the avalanche pulse with low timing jitter. The module can be operated also in free-running mode, with the SPAD always ON.
The main feature of the module is the possibility to increase the Dynamic Range of TCSPC systems thanks to a fast OFF-ON transition. Thus, weak signals can be extracted out of a huge background by enabling the detector only in well-defined time-windows. The good photon detection efficiency and timing resolution are obtained through both the use of epitaxial SPAD and the microwave layout optimized to reduce the effect of voltage oscillations following the fast gate transitions.
The FastGatedSPAD module is controlled through a PC software interface where it is possible to set all the relevant gate parameters (int./ext. trigger, gate frequency, gate width) and all the detector’s parameters: temperature, excess bias and hold-off time. In this way, it is possible to adjust the detector performances in terms of DCR, hold-off time and photon detection efficiency, in order to properly match the requirements of the user application.
Main module features:
- 50µm active sensing area diameter
- DCR < 200 c/s
- Timing jitter: FWHM as low as 50 ps; FWHM/1000 as low as 450 ps
- Detection efficiency: 50% @ 400 nm, 5% @ 800 nm
- Gated and Free-running modes of operation
- Gate rise-time: < 300 ps
- Gate repetition frequency: up to 80 MHz
- Free Space and Fiber Receptacle versions available
- Uniform performances all-over the active area
DATASHEET – FastGatedSPAD
PDM-IR
The PDM-IR is a photon counting module based on an InGaAs/InP Single-Photon Avalanche Diode (SPAD) for the detection of near-infrared single photons up to 1700 nm. The module includes a programmable frequency and pulse generator for gating the detector, a front-end circuit for photodetector’s avalanche sensing, a fast circuit for detector’s avalanche current quenching and operative bias voltage resetting and some sub-circuits for signal conditioning. All the main parameters and delay paths are adjustable by the user through the software interface, in order to match the requirements of different applications. The system can be conveniently used both for counting and timing measurements, since the high-performance electronics guarantees a clean temporal response even with fast gate transitions. PDM-IR can work either in free-running or in gated mode and the optical interface can be chosen between a free space and a pigtailed version.
The PDM-IR can be used either in gated or in free-running mode. Both modes of operations can be optimized through the use of several user selectable parameters, all controllable from a computer using either the delivered SDK library or the provided Windows® PC software.
When used in gated, the TRIGGER GATE signal, for GATE frequency generation, can be provided either using an INTERNAL TRIGGER or through an external signal fed into the TRIGGER IN input. Complex external trigger patterns can be also fed to the TRIGGER IN input, since it accepts not only periodic but also aperiodic signals. Additionally, it is possible to create even more complex TRIGGER GATE patterns for GATE generation, by combining the auxiliary input AUX IN signal with the INTERNAL TRIGGER or the TRIGGER IN, and by using the provided user-selectable logic. Finally, GATE signal can be generated either by exactly replicating TRIGGER GATE or by creating a new signal, synchronized with the rising edge of TRIGGER GATE and with a programmable fixed gated-ON width.
When used in free running mode the SPAD is always on until a SPAD avalanche is initiated. In this case, the avalanche current is first quenched and then, after a well-defined programmable hold-off, the detector is immediately enabled.
Concerning the SPAD parameters Hold-OFF time, excess bias voltage and SPAD temperature, they are all user selectable to get the best results from the measurement
Concerning the outputs: PHOTON OUT is the low timing jitter output signal, precisely marking the photon detection time; NIM AUX OUT and TTL AUX OUT, instead, shouldn’t be used for low jitter timing measurement and the output signal can be chosen independently, on each out channel, among TRIGGER GATE, INTERNAL TRIGGER, VALID GATE, PHOTON OUT and HOLD OFF signals.
Independently on the chosen PDM-IR mode of operation, the module has also internal counters that continuously monitor the following signals: TRIGGER IN, AUX IN, INTERNAL TRIGGER, PHOTON OUT and VALID GATE.
Finally, in the PDM-IR, all the main signal paths have a programmable delay, designed to help the user in synchronizing the various signals between them and with the external instruments. This feature is very helpful in many applications as it allows to avoid the hassle of continuously changing the cable length.
At MPD, a technical contact is always available for discussing with customers how to exploit at best the MPD technology in order to obtain the most accurate scientific results from their experimental set-ups.
Main module features:
- Sensitivity up to 1700 nm
- Based on InGaAs/InP SPAD (Free space and fibre-pigtailed versions available)
- Adjustable SPAD parameter (excess bias, temperature and hold-off)
- Adjustable Gate settings (gate width and frequency, external/external trigger reference) – gate module only
- Trigger reference up to 133 MHz and gate widths as low as 1.5ns – gate module only
- Timing jitter down to less than 100 ps FWHM
- PC software interface
DATASHEET
APPLICATION NOTES – TCSPC measurements
USER MANUALS
Picosecond Delayer
The MPD Picosecond Delayer is a module capable to generate output pulses (both NIM and TTL) with user-selectable delay and output pulse duration, in respect to the rising or falling edge of an input signal.
This new instrumentation, completely based on solid-state components, sets a new milestone with best in class precision, stability and time-jitter over a wide range of temperatures, not even matched by normal coaxial cables.
The delayer features a 50 ns nominal full scale range with a 10 ps step delay resolution, whilst the pulse duration is also user controllable from 1 ns to 250 ns with a nominal step of 3.3 ns.
The excellent integral non linearity error is comprised between +50 ps and -100 ps over the full scale range and for all operating temperatures. This exceptional performance makes the picosecond delayer the perfect choice for any experimental set-up where signals must be delayed with high accuracy and stability of characteristics over a broad range of delays and temperatures.
The low random jitter makes it also succesfully suitable in any Time Correlated Single Photon Counting application.
The picosecond delayer is available either as standalone module or as OEM electronic board. In this latter case the delayer is either controlled by a very simple software interface or, since the commands are ASCII strings sent over a virtual COM, by any user program able to communicate with a RS-232.
Main module features:
- 50 ns maximum delay range
- 10 ps step
- TTL and NIM output pulses
- up to 390 MHz bandwidth (NIM output)
- programmable output width
- INL between +50 ps and -100 ps over full-scale range and for all temperatures
- random jitter typ. 5 ps RMS
- < 1 ms programming time
- USB interface
- All solid state, no coax cables
Typical applications requiring flexible and adjustable delays between I/O signals are:
- LIDAR
- TCSPC measurements
- STREAK camera synchronization
- Correlation measurements
- Time Resolved measurements
- Short gate acquisition experiments
- Spectroscopy
- Optical Tomography
DATASHEET
Module Data Sheet
OEM Data Sheet
USER MANUALS
Module User Manual
OEM User Manual
NIM2TTL Converter
MPD NIM 2 TTL converter is a module capable to convert an input NIM pulse to a Low Voltage TTL output pulse with the same width.
This new instrumentation, completely based on solid-state components, fully maintains the input time-jitter performance without the typical drawbacks of passive pulse inverters at high pulse rates.
DATASHEET – NIM2TTL
