User`s guide

Performance Tests Performance Tests

Agilent 81618A/9A and Agilent 81623B/4B/6B/8B Optical Heads, Fourth Edition

Test Setup

Perform the test until the power reading of the DUT shows:

for 81623B: -47.x dBm

for 81624B: -57.x dBm

for 81626B: -37.x dBm

for 81628B: -57.x dBm (without sphere)

1 Make sure that cable connector, detectors and adapters are clean.

2 Make sure that you perform this test in a temperature-controlled

environment with temperature fluctuations less than ±1°C.

3 Setup the equipment as shown in Figure 9 . Disable both attenuators

and enable the laser source, where the source wavelength is chosen to

1550 nm. If you are using the 81657A, move to the wavelength

parameter, [λ], press Enter, select the longer wavelength source

(1550 nm nominally), and press Enter.

4 Set the wavelength of both attenuators to the same wavelength as the

laser source.

5 Perform the following sub-procedure for both Power Meters:

a Move to the Power Meter channel.

b Move to the wavelength parameter, [λ], press Enter, enter the

wavelength of the laser source, and press Enter.

c Move to the calibration parameter, [CAL], press Enter, set the

calibration parameter to zero, and press Enter.

d Move to the averaging time parameter, [AvgTime], press Enter,

move to <100 ms>, and press Enter.

e Move to the power parameter, [P], press [Pwr unit], move to <dBm>,

and press Enter.

• Do not turn the laser off during the measurement!

• Clean all connectors carefully before you start with the measurement!

The linearity test checks the in-range linearity as well as the range

discontinuity. Therefore, two values are measured at the same power but

within different power ranges (range discontinuity) and two different

power values , one on the lower and the other on the upper limit of the

power range, are measured within the same power range (in-range

linearity).

NOTE