SPCM-AQ4C
Single Photon Counting Module 4 Channel Array
Key Features
· Peak photon detection efficiency at 650 nm: 60% typical
· Afterpulsing probability 0.5%
· Gated input
· TTL output
· FC fiber connector mounted and aligned on each detector
· 4 channels in one package
· Self-contained APD module with integrated electronics
· ROHS compliant
Applications
· Single molecule detection
· High throughput single photon experiments
· LIDAR
· Photon correlation spectroscopy
· Astronomical observation
· Optical range finding
· Adaptive optics
· Ultra sensitive fluorescence
· Particle sizing
· Quantum communication
The SPCM-AQ4C is a 4-channel photon counting card capable of detecting single photons of light over the wavelength range from 400 nm to 1060 nm. Each channel is independent from the others.
The SPCM-AQ4C uses a unique silicon avalanche photodiode (SLiK) that has a circular active area of 180 μm with a peak photon detection efficiency exceeding 60% at 650nm. Each photodiode is both thermoelectrically cooled and temperature controlled, ensuring stabilized performance despite changes in the ambient temperature.
The SPCM-AQ4C card uses an improved circuit with a peak count rate >4 M c/s for short bursts of time on all 4 channels and a count rate of 1.5 M c/s for continuous operation. There is a "dead time" of 50 nanoseconds (ns) between pulses. The module requires +2 Volts, +5 Volt, and +30 Volt power supplies. The output of each channel – a TTL pulse that is 4.5 Volts high (into a 50 Ω load) and 25 ns wide – is available at the card edge behind the circuit board. Each TTL pulse corresponds to a detected photon. All input and output signals are available at the card connector.
Excelitas Technologies supports custom requirements of this module in screening for dark count, after pulse, and peak photon detection efficiency. Contact us to discuss your special needs on the SPCM-AQ4C.
Table 1 Specifications of SPCM-AQ4C, @ 22 ºC, unless otherwise indicated
Parameter
Min
Typ
Max
Unit
Supply current(7)
@+2V
@+5V
@+30V
1.0
0.20
0.01
4.0*
3.0**
1.0**
0.04**
A
Maximum power consumption(7)
@+2V
@+5V
@+30V
2
1
0.3
6**
5**
1.2**
W
Supply voltages (1,7)
1.95
4.75
29
2
5
30
2.05
5.25
31
V
Case operating temperature (heat sink) (1, 3)
5
40
ºC
Active area (diameter) of each channel at minimum Pd
170
180
µm
Photon detection efficiency (Pd) at: 400nm
650nm
830nm
1060nm
1
45
35
1
2.5
60
45
1.5
%
%
%
%
Pd variation at constant case temperature (2hrs at 25 ºC)
± 1
± 3
%
Pd variation from 5 ºC to 40 ºC(3)
± 4
± 10
%
Dark Count per channel(4, 5)
500
Counts/second
Average dark count variation at constant case
temperature (6 hrs at 25 ºC) (4, 5, 6)
± 10
%
Average dark count variation at 5 ºC to 40 ºC
case temperature (4, 5, 6)
± 20
%
Single photon timing resolution per channel
600
ps
Dead time (count rate below 5M/c)
50
ns
Output pulse width
25
ns
Linearity correction factor (7) at 200 Kc/s
1 Mc/s
1.5 Mc/s
1.01
1.08
1.12
1.10
1.15
1.20
Afterpulsing probability
0.5
%
Gating turn-on delay before first edge of true output pulse (50Ω output)
60
75
ns
Gate turn-off delay for minimum last output pulse width of 10ns (50Ω output)
4
15
ns
Gating threshold voltage (at V supply = 5V)
Low level (sink current <1.6mA)
High level (Source current <5.5mA)
0
3.5
0.8
5.25
V
Refer to Operating Instructions below for noted items
Operating Instructions
1. Connection to incorrect voltage or reverse voltage may damage or destroy the module. The warranty is invalid where such damage occurs. The center contact of the barrel type power connector (corresponds 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 3.5W and a maximum power of 14W at high count rate and 40°C. Adequate heat sinking must be provided by clamping the module to a suitable heat sink via the holes in the module base. For the specification performance, the module case temperature must not exceed 40°C.
4. Bi-stability of the dark count: 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 PerkinElmer’s 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. When connecting power to the module, good grounding techniques must be observed. All ground connections for the +30V and
+5V supplies should connect through a single point on the user’s interface. All ground pins on the card edge connector should be used. The +2V grounds should be connected together at a single point, but should be separate and isolated from the grounds of the other supplies.
8. The actual photon rate could be calculated using the following equation, as indicated below:
Note # 8: Actual photon rate calculation
Table 2. Absolute Maximum Ratings
Supply voltages (1, 7)
@+2V
@+5V
@+30V
2.1V
5.5V
31.5V
Maximum count rate, continuous (per channel)
2Mc/s
Peak count rate, @25% duty cycle to 500ms (per channel)
5Mc/s
Peak light intensity (per channel)
10 4 photons per pulse and pulse width < 1ns
Case temperature (3)
-45 ºC/+50 ºC storage, +5 ºC /+40 ºC operating with heat sink
Table 3. Fiber Ordering Guide
Part Number
Fiber Type
Connector Type
Diameter
Numerical Aperture
Core
Cladding
Outer
SPCM-QC4
Multimode
FC/bare
62.5um
125um
2.5mm
0.27
SPCM-QC6
Multimode
FC/bare
100um
140um
2.5mm
0.29
SPCM-QC8
Multimode
as SPCM-QC6 but 905 SMA on free end
SPCM-QC9
Multimode
as SPCM-QC6 but FC connector on free end
Dimensional Outline
描述 [描述] 650nm时的峰值光子探测效率:60%(典型)<br />后脉冲概率0.5%<br />门输入<br />TTL输出