Hello,
I wanted to know if a lensed fiber can guide a light of wavelength (1550 nm) longer than the working wavelength of the fiber (780 nm).
Thanks.
Dear Muhamed A. Sewidan ,
each type of fiber has its own transmission window characteristics according to the material composition and the design of the fibre;
see for example Fig. 6 of:
http://www.olsontech.com/mr_fiber/fiber-history.htm
Even at the spectral sections, which are not labelled as window, you are able guide light, but you will experience a lot of losses here.
Attaching a lense will not change the fiber attenuation but you will be able to increase the light intensity at the input port of the fiber.
Best regards
G.M.
There is a funny an interesting point about optical fibers; theses days most fibers are monomode (well not really still two polarizations) and in principle the naked fiber itself has the lower cutoff frequency ZERO (HE11 mode) ; but this is very theoretical on fiber you may get cladding modes which go along those lines; but retain that the fiber is not strictly like a metallic waveguide which has a well defined lower cutoff frequency
Hi Muhamed..if you like we can discuss this point on the phone or zoom in more detail; I have been actively working on optical fiber stuff at Bochum university in germany in the mid 70 ths..I see that you are at some institute in Hannover..my e-mail :[email protected] and phone:+41 22 767 6667
The working wavelength of an optical fiber is determined by the properties of the core and cladding materials, as well as the diameter of the core. The core and cladding materials have a specific refractive index that determines the wavelength of light that can be guided through the fiber.
The working wavelength of a typical lensed fiber is around 780nm, which is in the near infrared region of the electromagnetic spectrum. This means that the fiber is designed to guide light with a wavelength around 780nm.
It is possible that the lensed fiber may still guide light with a wavelength of 1550 nm, but the performance is not guaranteed, and it would depend on the specific properties of the fiber and the lens. The attenuation and dispersion at 1550 nm would be higher than the working wavelength.
Additionally, the lensed fiber may not be able to focus the light into the core of the fiber at 1550 nm as effectively as it does at the working wavelength.
It is always best to check the specifications of the lensed fiber and consult the manufacturer to confirm if it can guide a light of wavelength (1550 nm) longer than the working wavelength of the fiber (780 nm) and under which conditions.
I hope this helps,
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=14647
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts