MKS Ophir FPS-1 User manual

FPS-1 Quick Reference
Wavelength, nm
Sensitivity A/W
FPS-1 spectral response without filters
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
400 500 600 700 800 900 1000 1100300200
1 General Description
The FPS-1 fast photodetector is designed to measure the
temporal behavior of pulsed lasers. The FPS-1 has two
modes of operation:
a. High speed and low sensitivity into 50Ωload with 1ns
response time.
b. High sensitivity into 10KΩwith 3µs response time.
Additional filters can be purchased for the FPS-1 to
adjust the sensitivity to the power level of the source.
The FPS-1 comes with a stand and base and fiber
adapters are available for the sensor as well.
1. Getting Started
Connections:
The FPS-1 can operate either from its internal battery or
from the wall plug power supply. If you want to operate
the FPS-1 from the power supply, plug the power supply
into the socket marked 12VDC. Connect the output BNC
to your oscilloscope with either 50Ω or 10KΩtermination
resistance (see section 2).
To switch the battery on and off:
Switch the toggle switch marked “BAT” to “on”.
To switch off, switch to “off”. Note that this only switches
the battery. If the FPS-1 is powered from the wall cube,
it will not be switched off with this switch.
Battery check:
To check the battery status, press the small push button
marked “BAT. STATUS”. If the green LED lights, the
battery is OK.
6. Spectral Response
A graph of the approximate relative spectral response of the
FPS-1 is given below. This graph represents the sensitivity
without the additional filters.
Fast Photodiode Detector
for Temporal Measurements
FPS-1
Ophir Optronics Solutions LTD.
Science-Based Industrial Park P.O.B. 45021,
Jerusalem 9145001, Israel
Phone [phone]
https://www.ophiropt.com/photonics
rev 1.0-4/23.Aug.20/be Ophir P/N 1J06055
175 X 210 mm

2. Power vs. Time Measurement
The peak power of nanosecond pulses is usually very high
and above the saturation level of the FPS-1. However, it
is not necessary to look directly at the beam to measure
properly. The beam can be scattered from a white surface
and the FPS-1 can be placed at a distance from the beam
to look at a small fraction of the beam. The distance from
the scattering surface and the FPS-1 can be varied to get a
good but not saturated signal. If the intensity is still too high,
or it is not convenient to measure scattered light, filters
are available to lower the laser intensity. See ordering
information in section 5.
To measure pulsed lasers with the FPS-1:
1. Verify that the unit is switched on and the battery is in
good condition.
2. If the laser pulse width is <3µs, make sure the BNC cable
is terminated with a 50Ωtermination. If the pulse is >3µs
and the signal is not large enough, you can terminate the
BNC cable with 10KΩin order to increase the voltage
level.
3. Try at first diffusing the laser beam off of a diffusive
white surface and placing the FPS-1 at a distance of
~20cm from the surface. If the peak intensity is still too
high, move the FPS-1 further away. If the intensity
is still too high, one or more filters are recommended
(see ordering information in section 5). If the intensity is
too low, move the sensor closer to the laser spot.
4. If you are measuring a laser pulse through a fiber and
are using the optional fiber adapter, first try the beam
with several filters in and remove them as necessary.
3. Changing the Battery
In order to save the non-rechargeable battery, the FPS-1
can be operated with the wall plug power supply. If the
battery is low, the “BAT. STATUS” light will not light up
when the button is pressed. This means the battery should
be changed. In order to change the battery, unscrew the
screw next to the BNC output, remove the battery and insert
a new A23 battery.
4. Maintenance
The detector probe should be periodically cleaned with
tissue and alcohol. Otherwise no other care is needed for
the instrument.
5. Specifications
Model FPS-1
P/N 7Z02505
Detector Silicon photodiode
Spectral range 193nm – 1100nm
Detector area 0.8mm²
Spectral response See graph in section 6
Performance Into 50Ωload Into 10KΩload
specifications
Risetime 0 – 90% 1ns 3µs
Sensitivity at peak 0.15V for 1W/cm² 60V for 1W/cm²
wavelength input input
Maximum output 10V
voltage
Output connection BNC
Power 12V A23 alkaline battery (40 hours
lifetime). Can also be operated from
12VDC wall cube power supply
(included).
Input Direct or scattered laser light or from
fiber optics.
Input thread SM1 thread. One SM1 to M20 adapter is
needed to fit FPS-1 to attenuators and
fiber adapters (see below).
Optional attenuators Description P/N
and fiber adapters IS6 7Z08289
(M20 thread) adapter
X10 nom. attenuator 7Z08200
X50 nom. attenuator 7Z08201
SM1 to M20 adapter 1G02259
SMA fiber adapter 1G01236A
FC, FC/APC fiber 7Z08229
adapter
ST fiber adapter 7Z08226
SC fiber adapter 7Z08227
Battery ALKALINE 12V 7E05067
55MAH A23, EURO
Wall cube power 220VAC 7E05003
supply 110VAC 7E05017
175 X 210 mm