C30902SH
High-speed solid state detectors for low light level applications
Key Features
· High quantum efficiency: 77% typical at 830 nm
· C30902SH and C30921SH can be operated in Geiger mode
· C30902EH/SH-2 version with built-in 905 nm filter
· C30902BH version with ball-lens
· Hermetically sealed package
· Low Noise at room temperature
· High responsivity – internal avalanche gains in excess of 150
· Spectral response range –(10% Q.E. points) 400 to 1000 nm
· Time response – typically 0.5 ns
· Wide operating temperature range -40°C to +70°C
· RoHS compliant
Applications
· LIDAR
· Range finding
· Small-signal fluorescence
· Photon counting
· Bar code scanning
The C30902EH series of avalanche photodiodes is ideal for a wide range of applications, including LIDAR, range-finding, small-signal fluorescence, photon counting and bar code scanning.
Excelitas Technologies’ C30902EH series of avalanche photodiodes is fabricated with a double-diffused “reach-through” structure. This structure provides high responsivity between 400 and 1000 nm as well as extremely fast rise and fall times at all wavelengths. The responsivity of the device is independent of modulation frequency up to about 800 MHz. The detector chip is hermetically-sealed behind a flat glass window in a modified TO-18 package. The useful diameter of the photosensitive surface is 0.5 mm.
The C30921EH is packaged in a lightpipe TO-18 which allows efficient coupling of light to the detector from either a focused spot or an optical fiber up to 0.25 mm in diameter. The hermetically-sealed TO-18 package allows fibers to be mated to the end of the lightpipe to minimize signal losses without fear of endangering detector stability. The C30902EH-2 or C30902SH-2, with hermetic TO-18 package with inline 905nm passband filter and the C30902BH, with hermetic ball lens, complete the C30902 family.
Both C30902SH and C30921SH are selected C30902EH and C30921EH photodiodes having extremely low noise and bulk dark-current. They are intended for ultra-low light level applications (optical power less than 1 pW) and can be used in either their normal linear mode (Vr < Vbr) at gains up to 250 or greater, or as photon counters in the “Geiger” mode (Vr > Vbr) where a single photoelectron may trigger an avalanche pulse of about 108 carriers. In this mode, no amplifiers are necessary and single-photon detection probabilities of up to approximately 50% are possible.
Photon-counting is also advantageous where gating and coincidence techniques are employed for signal retrieval.
Table 1. Electro-optical Characteristics
Test conditions: Case temperature = 22˚C, unless otherwise specification, see notes on next page.
Detector Type
C30902EH/C30902EH-2
C30902BH
C30921EH
C30902SH
C30902SH-2
C30921SH
C30902SH-TC
C30902SH-DTC
Parameter
Min
Typ
Max
Min
Typ
Max
Min
Typ
Max
Units
Photosensitive area
active diameter
active area
0.5
0.2
0.5
0.2
0.5
0.2
mm
mm²
Lightpipe characteristics (C30921)
Numerical aperture of light pipe
Index of refraction (n) of core
Core diameter
0.55
1.61
0.25
0.55
1.61
0.25
[no units]
[no units]
mm
Field of view α
with standard/ball lens window
(-2) with built-in 905 nm filter
with lightpipe (in air)
90
55
33
90
55
33
122
N/A
N/A
Degrees
Field of view α’
with standard window/ball lens
(-2) with built-in 905 nm filter
114
78
114
78
129
N/A
Degrees
Breakdown voltage, Vbr
225
225
225
V
Temperature coefficient of reverse bias,
Vr, voltage for constant gain
0.5
0.7
0.9
0.5
0.7
0.9
0.5
0.7
0.9
V/˚C
Detector Temperature (see note 2)
-TC
-DTC
0
-20
˚C
˚C
Gain (see note 1)
150
250
250
Responsivity
at 830 nm (not applicable for -2)
at 900 nm
70
55
77
65
117
92
128
108
128
108
A/W
A/W
Quantum efficiency
at 830 nm (not applicable for -2)
at 900 nm
77
60
77
60
77
60
%
%
Dark current, id
-TC (at 0 °C)
-DTC (at -20 °C)
15
30
15
30
15
2
1
30
nA
nA
nA
Noise current, in (see note 3)
-TC (at 0 °C)
-DTC (at -20 °C)
0.23
0.5
0.11
0.2
0.04
0.02
pA/√Hz
pA/√Hz
pA/√Hz
Capacitance
1.6
2
1.6
2
1.6
2
pF
Rise/Fall time, RL=50 Ω
10% to 90% points
90% to 10% points
0.5
0.5
0.75
0.75
0.5
0.5
0.75
0.75
0.5
0.5
0.75
0.75
ns
ns
TEC maximal drive current
-TC
-DTC
1.8
1.4
A
A
TEC maximal bias voltage
-TC
-DTC
0.8
2.0
V
V
Dark count rate at 5% photon detection
probability (830 nm)
(see Figure 9 and note 4)
5000
15000
1100 (-TC)
250 (-DTC)
15000
cps
Voltage above Vbr for 5% photon
detection probability (830 nm)
(see Figure 7 and note 4)
2
2
V
After-pulse ratio at 5% photon detection
probability (830 nm) (note 5)
2
15
2
%
Notes:
1. At the specific DC reverse operating voltage, Vop or Vr, supplied with each device and a light spot diameter of 0.25 mm (C30902EH, SH) or 0.10 mm (C30921EH, SH). Operated at this voltage, between 180 and 250V, the device will meet the electrical characteristic limits shown above.
2. The temperature of the thermistor in Kelvin can be calculated using the following equation: ,where R is the measured thermistor resistance in Ω,β=3200,R0=5100Ω,T0=298.15K and.
3. The theoretical expression for shot noise current in an avalanche photodiode is in = (2q (Ids + (IdbM² + PORM) F) BW)½ where q is the electronic charge, Ids is the dark surface current, Idb is the dark bulk current, F is the excess noise factor, M is the gain, PO is the optical power on the device, and BW is the noise bandwidth. For these devices F = 0.98 (2-1/M) + 0.02 M. (Reference: PP Webb, RJ McIntyre, JJ Conradi, “RCA Review”, Vol. 35 p. 234, (1974)).
4. The C30902SH and C309021SH can be operated at a substantially higher detection probability. (see Geiger Mode Operation section).
5. After-pulse occurring 1 µs to 60 seconds after main pulse.
Table 2 – Maximum Ratings
Parameter
Symbol
Min
Max
Units
Storage temperature
TS
-60
100
°C
Operating temperature
Top
-40
70
°C
Soldering for 5 seconds (leads only)
260
°C
Reverse current at room temperature
Average value, continuous operation
Peak value (1 s duration, non-repetitive)
200
1
µA
mA
Forward current at room temperature
Average value, continuous operation
Peak value (1 s duration, non-repetitive)
Maximum Total Power Dissipation
IF
5
50
60
mA
mA
mW
Electro-Optical Characteristics
商品属性 [波长] 400 to 1000 nm [封装方式] TO-18