StreakKamera

StreakKamera, or streak camera, is a high-speed imaging instrument used to record the temporal evolution of light pulses by converting time into a spatial coordinate on a detector. It is commonly used in ultrafast optics to measure pulse shapes with picosecond or sub-picosecond resolution.

In operation, a light pulse illuminates a photocathode inside a vacuum tube, releasing electrons proportional to the instantaneous light intensity. The electrons are accelerated and swept by a rapidly varying electric field, which displaces them along one axis according to their emission time. A detector, such as a phosphor screen or a fast camera, records the swept electron distribution as a two-dimensional image; one axis corresponds to time, the other to the spatial profile of the input beam.

The resulting streak image provides the temporal profile of the pulse. Time resolution depends on the sweep rate, electron optics, and detector performance, and typically ranges from a few picoseconds to sub-picosecond in specialized configurations. Some systems also offer single-shot measurements, while others acquire averaged data over many events.

Streak cameras are used in ultrafast laser spectroscopy, pump–probe experiments, plasma physics, accelerator physics, and telecommunications testing, as well as for characterizing fast light sources such as free-electron lasers.

Key components include the vacuum streak tube, photocathode, electron optics, fast sweep electrodes, and a readout detector. Proper calibration, alignment, and vacuum maintenance are essential. The instruments are costly and require skilled operation.

Developed in the mid-20th century, streak cameras remain a standard tool for time-resolved optical measurements. They are produced by specialized manufacturers and integrated into broader measurement systems.