Supercontinuum laser
Emits a configurable pulsed supercontinuum band as a collimated beam.
Open in the canvas →In the real world
A supercontinuum source produces light spanning hundreds of nanometres — often the whole visible range and beyond — while retaining the spatial coherence and collimation of a laser beam. It is, in effect, white light that behaves optically like a laser: it can be focused to a diffraction-limited spot and coupled into a single-mode fibre, neither of which a lamp of comparable bandwidth allows.
The broadening is not produced by the gain medium. A pump laser — typically a mode-locked oscillator delivering high peak power — is launched into a strongly nonlinear medium, most often a photonic crystal fibre engineered so that its zero dispersion wavelength sits near the pump. Over a few centimetres, a cascade of nonlinear processes redistributes the pump energy across a vastly wider spectrum: self-phase modulation broadens it initially, then soliton fission, Raman self-frequency shift, and dispersive wave generation extend the edges.
Because the process is pump-driven, the output inherits the pump's pulse train: a supercontinuum is emitted as pulses at the pump's repetition rate, not as steady light, even though it looks white. Spectral flatness and pulse-to-pulse stability vary considerably with how far into the anomalous-dispersion regime the source is driven.
Supercontinuum sources became practical laboratory instruments after photonic crystal fibre made it possible to place the zero-dispersion wavelength wherever the available pump happened to be, rather than the other way round. They are now standard in broadband spectroscopy, optical coherence tomography, and as tunable excitation sources for fluorescence microscopy, where a single box replaces a rack of discrete laser lines.
In OpticalSetup
The Supercontinuum laser replaces a single wavelength with a spectrum minimum and maximum, and emits a flat-top band between them. Downstream wavelength-selective elements — filters, dichroics, etalons, the spectrometer — integrate against that true flat profile rather than a centroid, so a 20 nm bandpass placed on a 400 nm-wide source transmits the fraction of power it actually overlaps.
Dispersive elements (prisms, gratings) sample the band at several discrete wavelengths and fan them out individually, each carrying its own wavelength-derived colour — which is why a prism turns this source into a visible rainbow even though the undispersed beam is drawn as a single broadband white line.
It carries the same pulse train as the Pulsed Laser, since a real supercontinuum inherits its pump's timing, but exposes no pulse duration of its own: that is a property of whatever generated the continuum upstream, which is not modeled here.
The spectrum is an idealized flat top, not a measured shape with the peaks, dips, and edge roll-off of a real continuum, and its shape does not change with pump power. No broadening is simulated: the band is declared, not generated from a pump and a nonlinear fibre. Pulse-to-pulse spectral noise, a real limitation of these sources, is not represented.