GSD is the world’s 1st one to introduce highpower Fiber Coupled Diode Laser for depilation. The laser generator locates inside the mainframe instead of handpiece.Therefore, laser energy is transferred by fiber to the handpiece. The R&D of FCD aims to solve the high damage rate of the traditional vertical laser stack.This innovation design ensures the machine a low damagerate, uniform energy distribution, long lifespan and easy maintenance.
What is Fiber Coupled Diode laser?
FCD (Fiber Coupled Diode) means the light generated by multiple diode laser are coupled into a single-core multimode fiber by micro lens array, in order to deliver light to the target place.
Fiber-coupled (also called fiber-integrated) diode lasers have several advantages:
The light exiting the fiber has a circular and smooth (homogenized) intensity profile and a symmetric beam quality, which is in many cases very convenient. For example, less sophisticated optics are required for generating a circular pump spot for an end-pumped solid-state laser.
It becomes possible to remove the laser diodes together with their cooling arrangements e.g. from a solid-state laser head, which can then be more compact, and more space is left for other parts at this place.
Defective fiber-coupled diode lasers can easily be replaced without changing the alignment of the device where the light is used.
Fiber-coupled devices can be easily combined with other fiber-optic components.
Types of Fiber-coupled Diode Lasers
Many diode lasers are thus sold in fiber-coupled form, with robust fiber coupling optics (e.g., a permanent laser-welded fiber attachment) built into the laser package. The used fibers and techniques differ very much for different diode lasers:
The simplest case is that of a VCSEL (vertical cavity surface-emitting laser), which usually emits a beam with high beam quality, moderate beam divergence, no astigmatism, and a circular intensity profile. A simple spherical lens is sufficient for imaging the emitting spot to the core of a single-mode fiber. The coupling efficiency can be of the order of 70–80%. It is also possible to couple directly (butt couple) the fiber to the emitting surface of the VCSEL.
Small edge-emitting laser diodes also emit in a single spatial mode, thus in principle also allowing efficient coupling to a single-mode fiber. However, the coupling efficiency can be significantly degraded by the ellipticity of the beam, if a simple spherical lens is used. Also, the beam divergence is relatively high in at least one direction, requiring a lens with relatively high numerical aperture. Another problem is astigmatism of the diode output, particularly for gain-guided diodes; this may be compensated with an additional weak cylindrical lens. With output powers of up to a few hundred milliwatts, fiber-coupled gain-guided LDs can be used for, e.g., pumping erbium-doped fiber amplifiers.
