DC source
A DC source gives a steady voltage: a bias for a modulator, an offset to add to a signal, or a set point to hold a laser's power at.
Ports
One output, out.
The model
Its output is a DC level and nothing else:
\[v(t) = V_0,\]with no tones and no noise. Like every signal, it is worked out in the steady state (see Electronics: signals).
Wired to a laser’s mod input it scales the laser’s power, \(P = P_0(1 + m V_0)\); to its fm input it tunes the laser’s frequency; to an EOM, a fibre EOM, a fibre stretcher or a chip’s phase shifter it adds a phase or moves the bias. As a parameter it can be swept, to step the light through its response.
Settings
| Field | Default | Meaning |
|---|---|---|
v | 1 | Voltage (V) |
From the tool's own tables, file format version 1: the names are those in a .jekray file.
Readouts
The panel gives its output in the steady state: the DC level, the five strongest tones (each one’s amplitude, rms and the phase of its cosine), and the noise, as a density at 1 kHz and in rms from 1 Hz to 1 GHz. Any notes, such as an input left unwired or an output past its limit, are listed under it.
Assumptions
- The source is ideal: no noise, no drift and no output impedance.
Related
- Signal generator.
- Bias tee, to add it to an RF signal.
- Electronics: drives.