: You ring a bell (Pump1), wait a bit, ring it again (Pump2) to invert the phase, then listen (Probe). If the bell’s pitch drifted in between, the echo is weaker. That drift = dynamics.
Practicalities came next. Anna listed essentials: ultrafast pulses (femtoseconds), stable delay lines, sensitive detectors, and careful calibration. She warned about artifacts—scattered light, unwanted cascades, and laser fluctuations—and gave Marco a short checklist: lock the timing, check phase stability, measure background signals, and calibrate spectral phases. : You ring a bell (Pump1), wait a
If linear spectroscopy is asking a person a single question and recording their answer, is eavesdropping on a conversation between three people to find out how they really feel about each other. Mukamel just provided the dictionary to translate that conversation. Practicalities came next
When you poke with three beams (wavevectors ( k_1, k_2, k_3 )), the polarization emits light in specific directions. The most famous is the : If linear spectroscopy is asking a person a