C10910 INSTRUCTION MANUAL Ver.1.19E
56
9-1-3-2
Installation of C1808-03
（
PIN DIODE HEAD
）
(1) Example of C1808-03 installation
The example of installation of C1808-03 is shown below. Laser light is branched by a
beam splitter etc. and one side is inputted into measurement for one side to
C1808-03. Refer to the following item for the notes at this time.
Fig. 9-2
branching of laser for trigger
(2) Adjusting the incident light level
Pay attention to the following points when inputting light to the C1808-03. First, set an
optical power of 3 mW
to 5 mW (λ: 800 nm). Then align the optical axis so that the
entire diameter of the laser beam is incident on the sensor of the C1808-03. Interpose
some means, such as an ND filter, in the laser beam to vary the light intensity.
When the optical axis was aligned so the entire diameter of the laser beam is incident
on the sensor of the C1808-03, this minimizes fluctuations in light intensity even if the
laser beam brightness is not uniform or there is dust or other objects along the laser
beam path.
Connect the output from the C1808-03 to the oscilloscope (50
Ω
input). Check that
the frequency matches the laser output and that there is little fluctuation in the signal
intensity. (See the figures below.) If you cannot obtain stable waveforms, then check
the C1808-03 power supply and wiring, and try changing the ND filter values. Find a
laser intensity that allows normal operation. The C1808-03 has an internal circuit that
suppresses phase noise caused by input power fluctuations, so the output signal will
differ from the sensor characteristics.
For measurement
For geration of synchronous signal
Pin Diode Head
Example laser system
Output waveform by appropriate power Output waveform by weak power
