DET40 Free-Space Bias Photodetector

1. Overview

The DET40 is a ready-to-use, high-speed photodetector for free-space optical systems. The unit consists of a circuit board, detector and RF connector in a compact aluminum housing. An SMA connector is used at the output to reduce size and maximize frequency response with a maximum bandwidth of 5 GHz.The detector is available in two spectral ranges, 320-1000 nm and 1000-1700 nm.

2. Features

• Five models cover the wavelength  range 320-1700nm
• Bandwidth from 100MHz to 5GHz
• Rise times from 3.5ns to 350ps
• Compact size

3. Applications

• Analog Microwave
• Laser Pulse Width Measurement

4. Specifications

Remarks:
a For 50Ω load

5. Schematic Block Diagram

6. Operating Procedures

• Adjust the voltage grid of the oscilloscope to 10mV/div and set the input impedance of the oscilloscope to 50Ω;
• Connect the output of the detector to the input of the oscilloscope with a coaxial cable;
• Ensure that the power received by the detector is within the saturation power, and then turn on the light source to be measured and align it with the photosensitive area;
• Observe the waveform of the oscilloscope.

Note: We use a load resistor R to convert the photocurrent I to a voltage V for viewing on an oscilloscope: V = I x R

Load resistance affects response speed, and for maximum bandwidth we recommend using a 50 ohm coaxial cable with a 50 ohm terminating resistor at the other end of the cable for impedance matching. If bandwidth is not important, the amount of voltage in a given light can be increased by gaining the load resistor. The length of the coaxial cable can have a profound effect on the response, so it is recommended to keep the cable as short as possible.

7. Response curve

8. Mechanical dimensions

41x30x14mm（Without connectors）

9. Shipping list