128
8163A/B, 8164A/B & 8166A/B Mainframes Programming Guide
4
Measurement Operations & Settings
command:
[:SOURce[
n
]][:CHANnel[
m
]]:AM:STATe[
l
]?
syntax:
[:SOURce[
n
]][:CHANnel[
m
]]:AM:STATe[
l
]?
description:
Returns the current state of amplitude modulation.
Use [l] to query the current state of modulation of the upper or lower wavelength laser source of a dual-wavelength laser
source or a return loss module with an internal dual-wavelength laser source. The default value of [l] is
1
, the lower
wavelength source. The upper wavelength source is denoted by
2
.
parameters:
none
response:
A
boolean
value:
0: modulation is disabled
1: modulation is enabled
example:
sour2:am:stat?
->
0<END>
affects:
All laser sources, DFB sources, tunable laser modules except 81950A, and return loss modules containing an internal
source.
command:
[:SOURce[
n
]][:CHANnel[
m
]]:AM:COHCtrl:COHLevel[
l
]
syntax:
[:SOURce[
n
]][:CHANnel[
m
]]:AM:COHCtrl:COHLevel[
l
]<wsp><value>[MIN | MAX | DEF]
description:
Sets the level of coherence, when using coherence control, on an arbitrary scale from 1 to 99.98%. A 100% coherence
level corresponds to maximum coherence length and minimum linewidth. The coherence level required for a specific
linewidth and coherence length can vary between modules.
parameters:
The excursion level as a percentage of its maximum value.
Also allowed:
MIN: minimum programmable value (0%)
MAX: maximum programmable value (100%)
DEF: default preset (*RST) value.
response:
none
example:
source2:am:cohc 50
affects:
DFB sources and Keysight 81960A, 81980A, 81940A, 81989A, 81949A
command:
[:SOURce[
n
]][:CHANnel[
m
]]:AM:COHCtrl:COHLevel[
l
]?
syntax:
[:SOURce[
n
]][:CHANnel[
m
]]:AM:COHCtrl:COHLevel[
l
]<wsp><value>?[MIN | MAX | DEF]
description:
Queries the current level of coherence, when using Coherence Control. Coherence is expressed on an arbitrary scale from
1 to 99.98%. A 100% coherence level corresponds to maximum coherence length and minimum linewidth.