Related Optical Terms and Definitions. For a complete list go to our
Terms and Definitions Page.
Absolute Wavelength Accuracy
Absolute Wavelength Accuracy is the maximum difference between the actual wavelength and the displayed wavelength of the Optical Source. Wavelength is defined as wavelength in vacuum.
A unit of measurement of optical power which indicates relative power. A -10 dB means a reduction in power by 10 times, -20 dB means another 10 times or 100 times overall, -30 means another 10 times or 1000 times overall and so on.
A unit of measure used to measure wavelength of light, meaning one one-billionth of a meter
Relative Intensity Noise (RIN)
Relative intensity noise (RIN), describes the instability in the power level of a laser. The noise term is important to describe lasers used in fiber-optic communication and LIDAR remote sensing. It is the square of the (spectrally resolved) RMS optical power amplitude divided by the measurement bandwidth and the square of the average optical power, expressed in dB/Hz.
Total Return loss
In an optical fiber, the loss that takes place at any discontinuity of refractive index, especially at an air-glass interface such as a fiber endface, at which a fraction of the optical signal is reflected back toward the source. RL = - 10log10 (Preflected/Preference)