Remote Operation
SENSe Subsystem Commands
[SENSe:]BANDwidthBWIDth:VIDeo <numeric_value> [HZKHZMHZGHZ]
[SENSe:]BANDwidthBWIDth:VIDeo?
Specifies the bandwidth of the
3 kHz and the bandwidth of the currently selected transimpedance amplifier. Available choices move in a 1, 3, 10 sequence.
[SENSe:]BANDwidthBWIDth:VIDeo:AUTO OFFON01
[SENSe:]BANDwidthBWIDth:VIDeo:AUTO?
The [SENSe:]BANDwidthBWIDth:VIDeo:AUTO command enables and disables automatic coupling of the video bandwidth.
Video bandwidth filtering occurs after detection of the light. In the autocou- pled mode, the video bandwidth has an extremely wide range. This allows the optical spectrum analyzer to avoid unnecessary filtering that would reduce the sweep speed more than required.
Normally, the video bandwidth is coupled to the sensitivity. Manually entering a video bandwidth breaks this coupling. The video bandwidth can be manually set from 100 MHz to 3 kHz, or the bandwidth of the currently selected tran- simpedance amplifier, whichever is less.
The following functions affect video bandwidth:
•Changing the sensitivity value.
•Changing the reference level.
•Turning autoranging ON or OFF.
The range of video bandwidth available in Auto mode is much greater than can be set manually from the front panel. A lower value of video bandwidth requires a longer sweep time. Because of the interdependence between the video bandwidth and sensitivity, it is recommended that either the sensitivity or the video bandwidth be changed, whichever is the most important to the measurement task being performed.
Because of the interdependence of sensitivity and video bandwidth, these parameters cannot be set individually. If one of the parameters is set manually, the other is forced into Auto coupled mode and set by the instrument. Set either the desired sensitivity or the desired video bandwidth, depending on which parameter is most important to the current measurement task.
The Preset state of the video bandwidth coupling is AUTO.