Single crystals of sodium chloride are excellent for what type of infrared use?

Single crystals of sodium chloride (NaCl) are particularly useful in the field of infrared spectroscopy for far-infrared (FIR) applications. This is primarily due to their favorable optical properties, which include high transparency in the FIR region and minimal absorption of infrared light. NaCl crystals can effectively transmit FIR radiation, making them ideal for optical windows and lenses used in FIR spectroscopy.

In FIR applications, the low thermal noise of these crystals allows for accurate measurement of spectroscopic data. Their ability to withstand high power densities without significant thermal damage also enhances their utility in various experimental setups involving FIR radiation. These characteristics collectively make sodium chloride a preferred material for investigations in the far-infrared wavelength range.