The simulator demonstrates that spontaneous emission rate is not fixed but emerges from Fermi's golden rule applied to the local density of photonic states, showing in real time how tuning a cavity's quality factor, mode volume, and detuning from the emitter's transition frequency enhances or suppresses the emission rate relative to free space, quantified by the Purcell factor.
Set the emitter's natural transition frequency and its free-space emission rate, then adjust the cavity's quality factor and mode volume to see the resulting Purcell factor and enhanced decay rate calculated live. Sweep the cavity's resonant frequency away from the emitter's transition to see enhancement fall off and, past a threshold, watch how a photonic-bandgap-style zero-density-of-states region suppresses emission below the free-space rate. Watch the accompanying density-of-states plot and decay-curve animation update as you change each parameter.
Sliders for emitter transition frequency, free-space emission rate, cavity resonant frequency (detuning), cavity quality factor Q, and cavity mode volume V, plus a toggle to switch between resonant-cavity mode and photonic-bandgap-suppression mode; live readouts show the computed Purcell factor, enhanced or suppressed decay rate, and a real-time density-of-states and decay-curve visualization.
Did you know that Edward Purcell's original 1946 paper on this effect was only a few sentences long and said nothing about light at all? It concerned nuclear spins relaxing inside a radiofrequency resonant circuit; the leap to optical microcavities and single-photon sources came decades later, once scientists realized the same golden-rule logic about density of states applies equally to radio waves and to visible light.
The simulator demonstrates that spontaneous emission rate is not fixed but emerges from Fermi's golden rule applied to the local density of photonic states, showing in real time how tuning a cavity's quality factor, mode volume, and detuning from the emitter's transition frequency enhances or suppresses the emission rate relative to free space, quantified by the Purcell factor.
The simulator demonstrates that spontaneous emission rate is not fixed but emerges from Fermi's golden rule applied to the local density of photonic states, showing in real time how tuning a cavity's quality factor, mode volume, and detuning from the emitter's transition frequency enhances or suppresses the emission rate relative to free space, quantified by the Purcell factor.
Set the emitter's natural transition frequency and its free-space emission rate, then adjust the cavity's quality factor and mode volume to see the resulting Purcell factor and enhanced decay rate calculated live. Sweep the cavity's resonant frequency away from the emitter's transition to see enhancement fall off and, past a threshold, watch how a photonic-bandgap-style zero-density-of-states region suppresses emission below the free-space rate. Watch the accompanying density-of-states plot and decay-curve animation update as you change each parameter.
Did you know that Edward Purcell's original 1946 paper on this effect was only a few sentences long and said nothing about light at all? It concerned nuclear spins relaxing inside a radiofrequency resonant circuit; the leap to optical microcavities and single-photon sources came decades later, once scientists realized the same golden-rule logic about density of states applies equally to radio waves and to visible light.