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4 - quadrant photo detectors PD1 and PD2


The small board with soldered PD IC can be mounted into home-built AFM or SNOM set-up's. The sensitivity is optimized for 2 mW lasers at 670 nm wave length. It can be changed in dependence on the costumers requirements. The housing of the PD is on ground potential. We provide the blank board with 4 mm laboratoy connectors for the power supplyand with BNC connectors for the signals. As the application can need different band width or smaller noise, we make costumer specific boards. The full data sheet is provided.

enlarge image of Photodetector board
Basic Data:
voltage supply: 12V
detector type: QD7-5 (R&S 652 027)
amplification: 47 kOhm
outputs:4 x BNC
Properties of the Photo Diode:

active diameter: 3 mm
active area: 7 mm*mm
inactive spacing: 0,2 mm
sensitivity: 0,5 A/W (typ.)
wave length for maximum sensitivity: 820 nm
spectral range: 430 nm ... 900 nm
dark current (VR = 1 V): 0,03 nA typ., 3 nA max.
capacitance: 80 pF (Vs = 0 V)
Electronic Board:

type: current voltage converter
amplification: typical: 10 V/mA (10 kOhm)
band width: > 300 kHz
output noise: < 10 mVpp
dimensions: 15 mm x 26 mm

typical applications
laser deflection for displacement detection
(AFM, SNOM, micromechanics)
There are two types:
PD shape 1
PD 1
pd shape 2
PD 2
T = Top, B = Bottom, L = Left and R = Right, or TL = Top-Left.