New Focus 1480, Руководство пользователя, Страница: 7 / 20

15-GHz & 25-GHz Photodetectors Operation • 7
Quick Start
Use the Models 1480 and 1481 high-speed GaAs
photodetector modules for detecting light in the
wavelength range from 400 to 870 nm. Each module is
50-
Ω
terminated and has an internal battery and bias
circuitry to make it self-contained—no additional
power supply or bias circuitry is needed.
To operate the module, follow these quick-start
instructions or consult the other sections of this
manual for more detail.
1.
Take proper precautions to avoid electrostatic
damage to the photodiode. (See “Handling Precau-
tions” on page 6.)
2.
Remove the module from its case.
3.
Turn on power using the “Off/On” switch.
If you are using the detector for the first time, or you
wish to check the battery and DC offset, perform steps
4, 5 and 6
4.
Connect a voltmeter to the “Bias Monitor” SMA
connector.
5.
Press the “Batt Chk” button. The voltage should be
at least 3.5 V.
6.
Release the “Batt Chk” button. Without an optical
input, the voltage should be less than 10 mV.
7.
Connect the photodetector module to your
measurement instrument, being careful not to
over-torque the K-connector. The instrument must
have a 50-
Ω
input impedance.
8.
Check that the optical power emerging from your
fiber is below the cw Saturation Power, as
appropriate, to ensure detector linearity and to
avoid detector damage. (See “Characteristics” on
page 11
.
)
1480 FC Det revA.fm Page 7 Monday, March 13, 2000 2:55 PM