The name is absent



12


scanning
optical
delay line

femtosecond laser



Figure 2.3 : A schematic of a typical transmission-mode raster-scan time-domain
imaging system.


waveforms can be acquired, since this often determines the time for forming an image.
Typically, a motorized scanning stage is used to raster the object to be imaged through
the terahertz beam focus, so that image data is acquired one pixel at a time. In the
earliest example, THz waveforms were measured at a rate of 20 waveforms per second,
so acquiring a 100 × 100 pixel image took close to 10 min. This rate was determined
by the scan rate of the optical delay line, a galvanometric scanner with a corner
cube mirror. Modern THz imaging systems which use this raster-scanning method
employ more sophisticated methods for generating optical delay, and thus can run at
substantially higher speeds. In such systems, however, there is frequently a trade-off
between the scan range (as measured in picoseconds) and the scan rate (number of



More intriguing information

1. Analyzing the Agricultural Trade Impacts of the Canada-Chile Free Trade Agreement
2. Stable Distributions
3. Structural Breakpoints in Volatility in International Markets
4. Ultrametric Distance in Syntax
5. The name is absent
6. The name is absent
7. Improvements in medical care and technology and reductions in traffic-related fatalities in Great Britain
8. The name is absent
9. An Economic Analysis of Fresh Fruit and Vegetable Consumption: Implications for Overweight and Obesity among Higher- and Lower-Income Consumers
10. Two-Part Tax Controls for Forest Density and Rotation Time