Center Wavelength and Bandwidth
Thorlabs currently offers OCT systems that operate with a center wavelength of either 900 nm, 930 nm or 1300 nm. The center wavelength contributes to the actual imaging depth and resolution of the system. Shorter wavelength OCT systems, such as our 930 nm or 900 nm systems, are ideal for higher resolution imaging compared to systems with a center wavelength of 1300 nm. For imaging samples that have higher optical scattering properties, such as tissue, the longer wavelength systems are recommended. The longer center wavelength is not affected by scattering, and therefore, the light is able to penetrate deeper into the sample and return for detection.
The spectral bandwidth of the OCT light source is indirectly proportional to the axial (depth) resolution of the imaging system. Therefore, broadband light sources are used to provide high axial resolution.