Measurement Operations & Settings Signal Generation – The SOURce Subsystem
124 Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Fifth Edition
command: [:SOURce[ n]][:CHANnel[m]]:POWer:ATTenuation[l]:DARK?
syntax: [:SOURce[n]][:CHANnel[m]]:POWer:ATTenuation[l]:DARK?
description: Queries whether the attenuator is set to ‘d ark’ position (where all light is blocked by the la-
ser).
parameters: none
response: 0:
1:
dark position not set
dark position set
example: sour0:pow: att:dark? → 1<EN D>
affects: All tunable laser modules with a built-in optical attenuator.
command: [:SOURce[n]][:CHANnel[m]]:POWer[:LEVel][:IMMediate][:AMPLitude[l]]
syntax: [:SOURce[n]][:CHANnel[m]]:POWer[:LEVel][:IMMediate] [:AMPLitude[l]]<wsp><value>
[PW|NW|UW|MW|Watt|DBM]
description: Sets the power of the laser output.
NOTE If an optical attenuator is installed, the p ower value returned is depende nt on whether you
are using power or attenuation mode (see
“[:SOURce[n]][:CHANnel[m]]:POWer:ATTenuation[l]:AUTO” on page 123).
If you are using power mode, the value returned is the output power.
If you are u sing att enuat ion mode , the va lue ret urned is the las er outpu t power, a nd you must
also use the attenuation value to ca lculate the output power (see
“[:SOURce[n]][:CHANnel[m]]:POWer:ATTenuation[l]” on page 122).
The values for the output power that you set in the Power Mode, and the laser output po wer
that you set in the Attenuation M ode, are stored and used inde pendently.
NOTE The instrume nt may n ot be abl e to out put a sig nal wit h the max imum p rogram mable po wer, it
will output a signal with the max imum power. Use the
“[:SOURce[n]][:CHANnel[m]]:POWer[:LEVel][:IMMediate][:AM PLitude[l]]?” on page 125 to
query the power being output.
The default units are DBM or W, depending on the unit selected usin g the following com-
mand: “[:SOURce[n]][:CHANnel[m]]:POWer:UNIT” on page 127.
parameters: Any value in the specified range (see the appropriate User’s Guide).
Also allowed are: MIN: minimum programmable value
MAX: maximum programmable value
DEF: This is not the preset (*RST) default value, but is the maximum
programmable level
NOTE Use [l] to set the amplitude level of the output power of the upp er or lower wavelength laser
source of a dual-wavelength laser source or a return loss module with an internal dual-wave-
length laser source. The defau lt value of [l] is 1, the lower wavele ngth source. The upper
wavelength source is denoted by2.
response: none
example: sour2:pow 23uW
affects: All tunable laser and DFB source modules