Infrared Calculator

Convert between wavelength, frequency, and wavenumber for infrared radiation.

IR Parameters

μm
THz
cm-1

Infrared Radiation Concepts

Infrared radiation is a part of the electromagnetic spectrum. It is often characterized by its wavelength, frequency, or wavenumber, especially in spectroscopy.

Key Formulas:

  • Speed of Light: c = λ × f
  • Wavenumber: ˜ν = 1 / λ

Where:

  • c = Speed of light in vacuum (2.998 × 108 m/s)
  • λ = Wavelength (meters)
  • f = Frequency (Hz)
  • ˜ν = Wavenumber (m-1 or cm-1)

Infrared Spectrum Regions

Region Wavelength Range Frequency Range Wavenumber Range
Near-Infrared (NIR)0.75 - 1.4 μm214 - 400 THz7143 - 13333 cm-1
Short-wave Infrared (SWIR)1.4 - 3 μm100 - 214 THz3333 - 7143 cm-1
Mid-wave Infrared (MWIR)3 - 8 μm37.5 - 100 THz1250 - 3333 cm-1
Long-wave Infrared (LWIR)8 - 15 μm20 - 37.5 THz667 - 1250 cm-1
Far-Infrared (FIR)15 - 1000 μm0.3 - 20 THz10 - 667 cm-1

Frequently Asked Questions

What is infrared radiation?

Infrared (IR) radiation is a type of electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves. It is primarily associated with heat and is emitted by all objects with temperature above absolute zero.

How are wavelength, frequency, and wavenumber related in IR?

These are all ways to describe infrared radiation. Frequency (f) and wavelength (λ) are inversely related by the speed of light (c): f = c/λ. Wavenumber (ṽ) is the spatial frequency of a wave, defined as 1/λ, and is often expressed in cm⁻¹.

What are the applications of infrared?

Infrared has numerous applications, including thermal imaging (night vision, medical diagnostics), remote controls, fiber optic communication, spectroscopy (IR spectroscopy for chemical analysis), heating, and astronomy.