435 Route 206 • P.O. Box 366
Newton, NJ 07860-0366
Ph. 973-579-7227
FAX 973-300-3600
FDS100 Si Photodiode
High Speed
Large Active Area
The FDS100 is a high-speed silicon photodiode with a spectral response from 350nm to over 1100nm.
This photodiode has a PIN structure that provides fast rise and fall times with a bias of 20V.
(Ø0.32")
Electrical Characteristics
Spectral Response:
Active Area:
Rise Time (RL=50Ω):
Fall Time (RL=50Ω):
NEP@900nm:
Dark Current:
Package:
350-1100nm
13.0mm²
10ns (20V bias)
10ns (20V bias)
1.2 x 10-14 W/√Hz
(@20V bias)
20nA max (20V)
T05, 0.36” can
38.10
(1.50")
3
cathode
anode
case
Maximum Ratings
Damage Threshold CW:
Damage 10ns Pulse:
Max Bias Voltage:
1.52
(0.06")
Ø5.84
(Ø0.23")
2.03
(0.08")
2
Ø0.46
(Ø0.018")
1
100 mW/cm2
500mJ/cm²
25V
45°
Ø5.08
(Ø0.20")
3
Ø9.14
(Ø0.36")
Pin Description
1
2
1. Laser anode
2. Laser case
3. Laser cathode
Bottom view
10.16
(0.40")
The Thorlabs FDS100 photodiode is ideal for measuring both pulsed and CW light sources, by converting
the optical power to an electrical current. The Si detector is housed in a T05 can, with an anode, cathode
and case connection. The photodiode anode produces a current, which is a function of the incident light
power and the wavelength. The responsivity ℜ(λ), can be read from Figure 1 to estimate the amount of
photocurrent to expect. This can be converted to a voltage by placing a load resistor (RLOAD) from the
photodiode anode to the circuit ground. The output voltage is derived as:
Vo = P * ℜ(λ) * RLOAD
The bandwidth, fBW, and the rise time response, tR, are determined from the diode capacitance, CJ, and
the load resistance, RLOAD, as shown below. Placing a bias voltage from the photo diode cathode to the
circuit ground can lower the photo diode capacitance.
fBW = 1/(2π * RLOAD *CJ), tR = 0.35/fBW
0637-S01 Rev D 4/4/03
Typical Circuit Diagram
Noise Filter (Typical Values)
FDS100
+
1K
RLOAD
0.1UF
-
Typical Plots
Figure 1 - FDS100 Spectral Responsivity Curve
0.7
Responsivity (A/W)
0.6
0.5
0.4
0.3
0.2
0.1
0
300
400
500
600
700
800
900
1000
Wavelength (nm)
Typical Responsivity Curve using Thorlabs calibration services.
0637-S01 Rev D 4/4/03
1100