SPCM-AQRH
Single Photon Counting Module
Key Features
· Peak PDE: > 70% @ 700nm
· 180µm active area
· > 35 Mcps dynamic range
· Gated output
· Single +5 V supply
· RoHS-compliant
· Low after pulse probability
· High uniformity over large active area
· Unmatched linearity
· Free space window, FC fiber adaptor, C-mount bracket,
Tube cage mount bracket options
Applications
· LIDAR
· Quantum Cryptography
· Photon correlation spectroscopy
· Astronomical observation
· Optical range finding
· Adaptive optics
· Ultra-sensitive fluorescence
· Particle sizing
· Microscopy
SPCM with free space window (right) and with FC adaptor (left), with tube cage mount bracket and C-mount bracket
Excelitas Technologies’ newly improved SPCM-AQRH Single Photon Counting Module detects single photons over the wavelength range of 400nm to 1060nm with performance parameters superior to other solid state or vacuum-tube based photon counters.
The SPCM-AQRH uses a unique silicon avalanche photodiode (SLiK) with a circular active area, achieving peak photon detection efficiency greater than 70% at 700nm over a 180µm diameter with unmatched uniformity over the full active area. A TTL level pulse is generated for each photon detected and the signal is available at the BNC connector at the rear of the module. The signal should be terminated into 50Ω.
The photodiode is both thermoelectrically cooled and temperature controlled, ensuring stabilized performance despite ambient temperature changes. Operating temperature range has been increased and the module (case temperature) will function between 5˚C and 70˚C.
The module comes with free space window, FC fiber adaptor, C-mount or tube cage mount bracket/adaptor options.
Recent electronic circuit improvements have reduced the minimum dead time to less than 25ns, thereby increasing linearity and improving the dynamic range of the module. Timing resolution of the module was also improved significantly. The SPCM- AQRH has internal protection circuitry that protects the avalanche photodiode and the module electronics from damage due to accidental overload from exposure to ambient lighting.
Excelitas’ series of photon counting modules are designed and built to be fully compliant with the European Union’s RoHS Directive 2011/65/EU.
Table 1. Specifications of SPCM-AQRH-WX, @ 22 °C, all models, unless otherwise indicated
Parameter
Min
Typ
Max
Unit
Supply voltage (1)
4.75
5.0
5.25
V
Supply current
0.4
1.2
A
Power cable total resistance
0.1
0.2
Ω
Case operating temperature (1, 3)
5
70
°C
Active area (diameter) at minimum PDE
170
180
µm
Photon detection efficiency (PDE)
(without FC adaptor)(10, 11) at: 400nm
650nm
830nm
1060nm
Refer to SPCM-NIR family for red – NIR
optimized/selected modules, see Figure 4
2
50
35
1
5
65
45
2
%
%
%
%
Dark Count (4, 5, 6)
SPCM-AQRH-W0
SPCM-AQRH-W1
SPCM-AQRH-W2
SPCM-AQRH-W3
SPCM-AQRH-W4
SPCM-AQRH-W5
SPCM-AQRH-W6
See table 3.
1500
1000
500
250
100
50
25
Counts / second
Output pulse width (9)
SPCM-AQRH-1X, SPCM-AQRH-4X
SPCM-AQRH-2X, SPCM-AQRH-5X
SPCM-AQRH-3X, SPCM-AQRH-6X
See table 3.
10
18
28
ns
ns
ns
Dead time (count rate below 5M/c)
SPCM-AQRH-1X, SPCM-AQRH-4X
SPCM-AQRH-2X, SPCM-AQRH-5X
SPCM-AQRH-3X, SPCM-AQRH-6X
See table 3.
22
28
35
ns
ns
ns
Output pulse amplitude:
SPCM-AQRH-1X, SPCM-AQRH-2X, SPCM-AQRH-3X
TTL HIGH
TTL LOW
See table 3.
1.5
-0.1
2.2
0.8
V
V
SPCM-AQRH-4X, SPCM-AQRH-5X, SPCM-AQRH-6X
TTL HIGH
TTL LOW
See table 3.
3.0
-0.1
4.4
0.8
V
V
Average dark count variation at constant case
temperature (6 hrs. at 25 °C) (4, 5, 6)
SPCM-AQRH-W0, W1, W2, W3
SPCM-AQRH-W4, W5, W6
± 10
± 1
%
s
Variation of average dark count rate at 5°C to 70°C
case temperature for (4, 5, 6)
SPCM-AQRH-W0, W1, W2, W3
SPCM-AQRH-W4, W5, W6
± 20
± 2
%
s
Single photon timing resolution (at 825nm)(12)
Please refer to SPCM-AQRH-TR family for
optimized timing modules
350
ps
Output count rate before saturation(8)
12
37
Mc/s
Afterpulsing probability(13)
0.5
1
%
Setting time following power up (1% stability)
at 1 Mc/s and 25°C
15
20
s
Linearity correction factor (7) at 200 Kc/s
1 Mc/s
5 Mc/s
10 Mc/s
20 Mc/s
25 Mc/s
1
1.02
1.16
1.40
2.35
3.32
Threshold setting required on counter for digital
output pulse (terminate in 50Ω)
1.0
V
Gating turn on/off (50Ω output)
Disable = TTL low (<0.8V)
Enable = TTL high (>2.0V)
40
60
45
65
ns
Gating threshold voltage (at V supply = 5V)
Low level (sink current >90mA)
High level (sink current >30mA)
0
2.0
0.4
5.25
V
Operating Instructions
1. Connection to incorrect voltage or reverse voltage may damage or destroy the module. The warranty is invalid should such damage occur. The center contact of the barrel type power connector (corresponding to the white stripe on the wire) is +5V.
2. These modules are not qualified for shock or vibration other than normal instrumentation environments.
3. The module dissipates a mean power of 2.0W and a maximum power of 6W at high count rate and 70°C. Adequate heat sinking must be provided by clamping the module to a suitable heat sink via the holes in the module base. To meet specified performance, the module case temperature must not exceed 70°C. See Figure 6 for stability of probability of detection vs. temperature.
4. On a small percentage of delivered modules, bi-stability of the dark count has been observed. Research indicates this bi- stability is probably due to transitions at a single impurity site between a low energy and a high energy state.
The phenomenon is seen as an abrupt change in the dark count rate, e.g., 350 to 390 c/s., and the dark count switches between the two states at a rate dependent upon the detector temperature. Multilevel switching has also been observed, where more than one impurity site is switching.
5. Long-term bi-stability is related to fundamental semiconductor physics and is beyond Excelitas’ control. Warranty claims will not be considered against bi-stability alone.
Warranty claims will only be considered if the high level of the dark count exceeds the maximum level in the specification.
6. In the dark, the module generates random counts that follow a Poisson distribution. In a Poissonian process, the standard deviation is equal to the square root of the average count. In this specification the “dark count variation” refers to the stability of the average count of the module.
7. The actual photon rate could be calculated using the following equation, as indicated in Note #7 in the box below. This parameter applies to the modules with dark counts of 100cps or higher.
Note # 7: Actual photon rate calculation
8. For the typical dead time setting of 22ns, typical maximum count rate is 37Mc/s before saturation. If the longest output pulse width option is set (28ns), the typical maximum count rate is 30Mc/s before saturation. If the maximum dead time setting is used, about 62ns, typical maximum count rate would be about 12Mc/s. Note that using a longer dead time will degrade linearity.
9. Output pulse width is set at the standard of 10ns ± 2ns at 2.2V. Other output pulse widths can be set. Please refer to Table 3, Ordering Guide, for which model number to order.
10. Output pulse height standard is set to 2.2V ± 0.4V. Optional output pulse height is 4.4V. Please refer to Table 3, Ordering Guide, for which model number to order.
11. If needed, an FC fibre adaptor can be factory installed on the SPCM-AQRH module allowing optical fibres to be used. The FC adaptor is optimized for use at 550 nm and with a 100µm core multimode fibre. If other wavelengths or fibre sizes are needed, please contact the factory for availability. The addition of an FC adaptor will cause a small drop in the effective PDE of the module. The amount of the loss will depend on the wavelength and the diameter of the fibre used to provide optical input to the module. Typically, one can expect around a 5% loss with a 100µm core fibre at 550nm.
12. Red-NIR wavelength photon detection efficiency can be optimized. PDE is enhanced over the 700-900nm wavelength range. Please refer to the Product Brief of the SPCM-NIR series. See Figure 4 for the typical photon efficiency of standard and enhanced PDE modules.
13. Timing resolution is measured using a 10µm diameter light spot, at 825nm, and with case temperature at 22°C. For timing resolution requirements of larger spot size measurement, or at different wavelengths, please contact Excelitas. For timing resolution optimized modules, please refer to the Product Brief of the SPCM-AQRH-TR series
14. Afterpulse is measured for the first 500ns (excluding the first 75ns) on the timeline of the afterpulse curve, at an average count rate of 100kc/s ± 20kc/s.
Table 2. Absolute Maximum Ratings
Supply voltage (1)
5.5 V
Maximum count rate
Maximum count rate can be sustained if case temperature is maintained within limit specified limits
Peak light intensity
maximum 104 photons / pulse, pulse width < 1ns
Case temperature (3)
-20°C/+85°C storage, +5°C /+70°C operating
SPCM Ordering Guide
Table 3A – Dark count and pulse width options:
Table 3B – Optical bracket/adaptor options:
Table 4. Fibre Ordering Guide
描述 [描述] 峰值PDE:> 70% @ 650 nm<br />180 µm感光面积<br />动态范围> 35 Mcps<br />可门控输出信号