EVERYTHING
IN A
NEW
LIGHT.
Description
PerkinElmer Type C30902E avalanche
photodiode utilizes a silicon detector chip
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. Because the fall time
characteristics have no "tail", 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.
PerkinElmer Type C30921E utilizes the
same silicon detector chip as the C30902E,
but in a package containing a lightpipe
which allows efficient coupling of light to the
detector from either a focussed spot or an
optical fiber up to 0.25 mm in diameter. The
internal end of the lightpipe is close enough
to the detector surface to allow all of the
illumination exiting the lightpipe to fall within
the active-area of the detector. The
hermetically-sealed TO-18 package allows
fibers to be epoxied to the end of the
lightpipe to minimize signal losses without
fear of endangering detector stability.
The C30902E and C309021E are designed
for a wide variety of uses including optical
communications at data rates to 1
GBit/second, laser range-finding, and any
other applications requiring high speed
and/or high responsivity.
Silicon Avalanche Photodiodes
C30902E, C30902S, C30921E, C30921S
High Speed Solid State Detectors for
Fiber Optic and Very Low Light-Level Applications
Features
High Quantum Efficiency 77% Typical at 830 nm
C30902S and C30921S in Geiger Mode:
Single-Photon Detection Probability to 50%
Low Dark-Count Rate at 5% Detection Probability - Typically
15,000/second at +22C
350/second at -25C
Count Rates to 2 x 106/second
Hermetically Sealed Package
Low Noise at Room Temperature
C30902E, C30921E - 2.3 x 10-13 A/Hz1/2
C30902S, C30921S - 1.1 x 10-13 A/Hz1/2
High Responsivity - Internal Avalanche Gains in Excess of 150
Spectral Response Range - (10% Points) 400 to 1000 nm
Time Response - Typically 0.5 ns
Wide Operating Temperature Range - -40C to +70C
Optical Characteristics
C30902E, C30902S (Figure 13)
Photosensitive Surface:
Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Circular
Useful area . . . . . . . . . . . . . . . . . . . . . . . . . .0.2 mm2
Useful diameter . . . . . . . . . . . . . . . . . . . . . . .0.5 mm
Field of View:
Approximate full angle for totally
illuminated photosensitive surface . . . . . . . . .100 deg
C30921E, C30921S (Figure 14)
Numerical Aperture of Light Pipe . . . . . . . . . . . . .0.55
Refractive Index (n) of Core . . . . . . . . . . . . . . . . .1.61
Lightpipe Core Diameter . . . . . . . . . . . . . . . . . . . .0.25 mm
Figure 2. Typical Quantum Efficiency vs. Wavelength
Figure 1. Typical Spectral Responsivity at 22C
C30902E, C30902S, C30921E, C30921S
The C30902S and C30921S are selected C30902E and
C30921E 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.
Maximum Ratings, Absolute-Maximum Values (All Types)
Reverse Current at 22C:
Average value, continuous operation
200 A
Peak value
(for 1 second duration, non-repetitive)
1 mA
Forward Current, IF at 22C:
Average value, continuous
operation
5 mA
Peak value (for 1 second
duration, non-repetitive)
50 mA
Maximum Total Power Dissipation at 22C
60 mW
Ambient Temperature:
Storage, Tstg
-60 to +100C
Operating, TA
-40 to +70C
Soldering (for 5 seconds)
200C
Figure 3. Typical Noise Current vs. Gain
Electrical Characteristics
1
at T
A
= 22C
C30902E, C309021E
C30902S, C30921S
Min
Typ
Max
Min
Typ
Max
Units
Breakdown voltage, V
BR
-225
-
-225
-
V
Temperature Coefficient of
VR for Constant Gain
0.5
0.7
0.8
0.5
0.7
0.8
V/C
Gain
-150
-
-250
-
Responsivity:
At 900 nm
55
65
-92
108
- A/W
At 830 nm
70
77
-117
128
- A/W
Quantum Efficiency:
At 900 nm
-60
-
-60
-
%
At 830 nm
-77
-
-77
-
%
Dark Current, I
d
-
1.5x10
-8
3x10
-8
-1x10
-8
3x10
-8
A
(Figure 6)
(Figure 6)
Noise Current, i
n
:
2
f = 10 kHz,
f = 1.0 Hz
-
2.3x10
-13
5x10
-13
-1.1x10
-13
2x10
-13
A/Hz
1/2
(Figure 3)
(Figure 3)
Capacitance, C
d
-1.6
2
-1.6
2
pF
Rise Time, t
r
:
RL = 50, = 830 nm,
10% to 90% points
-0.5
0.75
-0.5
0.75
ns
Fall Time:
RL = 50, = 830 nm,
90% to 10% points
-0.5
0.75
-0.5
0.75
ns
Geiger Mode (See Appendix)
Dark Count Rate at 5% Photon
Detection Probability
3
(830 nm):
22C
---
-
15,000
30,000
cps
-
25C
---
-
350
700
cps
Voltage Above VBR for 5% Photon
Detection Probability
3
(830 nm)
(See Figure 8)
-
-
-
-
2
-
V
Dead-Time Per Event
(See Appendix)
---
-
300
-
ns
After-Pulse Ratio at 5% Photon
Detection Probability (830 nm)
22C
4
-
-
-
-
2
15
%
Note 1. At the DC reverse operating voltage VR supplied with the device and a light spot diameter of 0.25 mm (C30902E, S) or 0.10 mm (C30921E, S). Note that a specific value
of VR is supplied with each device. When the photodiode is operated at this voltage, the device will meet the electrical characteristic limits shown above. The voltage value will be
within the range of 180 to 250 volts.
Note 2. The theoretical expression for shot noise current in an avalanche photodiode is in = (2q (Ids + (IdbM
2 + P
oRM) F) Bw)
1/2 where q is the electronic charge, I
ds 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)).
Note 3. The C30902S and C30921S can be operated at a substantially higher Detection Probabilities. See Appendix.
Note 4. After-Pulse occurring 1 microsecond to 60 seconds after main pulse.
C30902E, C30902S, C30921E, C30921S
Figure 4. Typical Responsivity at 830 nm vs. Operating Voltage
Figure 5. Typical Gain-Bandwidth Product vs. Gain
Figure 6. Typical Dark Current vs. Operating Voltage (V < VBR)
Figure 7. Avalanche Photodiode Response to a 100 ps Laser Pulse as
Measured with a 350 ps Sampling Head. (Horizontal Axis: 200 ps/Division)
Figure 8. Gelger Mode, Photoelectron Detection Probability vs. Voltage Above
VBR (VR > VBR)
C30902E, C30902S, C30921E, C30921S
Figure 9. Passively Quenched Circuit and Resulting Pulse Shape
Dimensions in millimeters. Dimensions in parentheses are in inches.
Figure 10. Load Line for C30921S in the Geiger Mode
Figure 11. Typical Dark Count vs. Temperature at 5% Photon (830 nm)
Detection Efficiency
Figure 12. Chance of an After-Pulse within the Next 100 ns vs. Delay-Time in
an Actively Quenched Circuit. (Typical for C30902S, C30921S at VBR + 25)
Modified TO-18 Package.
Note: Optical distance is defined as the distance from the surface of the silicon
chip to the front surface of the window.
Figure 13. Dimensional Outline - C30902E, C30902S, C30921E, C30921S
C30902E, C30902S, C30921E, C30921S
Figure 14. Cutaway of the C30921E, C30921S
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