Terminal block for high power fiber laser system
A fiber connector system provides a pigtailed monolithic terminal block of a fiber connector configured to alter a space distribution of laser output radiation. The output facet of the pigtailed monolithic terminal block is configured to alter the divergence of an output beam allowing collimation, focusing, or any desired distribution without additional optical circuitry. The fiber connector system is operative to couple two fibers from respective different fiber devices and allows positioning additional optical components there between.
1. A fiber connector system, configured to alter a space distribution of a laser radiation passing there through, the fiber connector system comprising:
an input optical fiber configured to transmit an input of the laser radiation along a light path; and
at least one monolithic block having an input facet fused to the fiber which provides the received laser radiation with a first divergence distribution relative to a first optical axis of the one terminal block as the laser radiation propagates along the block, the one monolithic terminal block having an output facet configured with an aspherical surface to spatially shape the laser radiation having the first divergence distribution, the aspherical surface being configured as a diffraction grating element or a Fresnel-zone plate and having an elliptical rotation which is effective to eliminate spherical aberrations relative to the optical axis,
a central cross section of the aspherical surface being described by equation (I)
z
=
c
r
2
1
+
1
-
(
1
+
k
)
c
2
r
2
(
I
)
wherein:
k
=
-
1
n
2
1
c
=
R
=
L
n
-
1
n
n—refractive index of the terminal block, L=length of the terminal block, c=value inversely equal to the radius of the aspherical surface in the vicinity of the optical axis of the terminal block, and R=radius of aspherical surface in the vicinity of the optical axis of the terminal block.
2. The fiber connector system, according to claim 1 , further comprising:
a second monolithic block positioned along the optical axis of the first terminal block and configured to receive the shaped laser radiation and operative to alter the received shaped laser radiation relative to the optical axis, the second monolithic terminal block being configured with:
an input facet receiving the shaped laser radiation and configured to converge the received shaped laser radiation from the first monolithic terminal block,
a planar output facet on the second terminal block opposite the input facet; and
an output optical fiber fused to the planar output facet,
the input facet being configured to focus the received shaped laser radiation so as to enter the output optical fiber coupled into the planar output facet, whereby the laser radiation is coupled from the first input fiber to the output optical fiber.
3. The fiber connector system of claim 2 further comprising an intermediate optical element spaced between one and second monolithic blocks and configured to not alter the shaped laser radiation.
4. The fiber connector system of claim 2 , wherein the one and second terminal blocks have respective optical axes extending parallel to one another so that the axes are either aligned or misaligned.
5. The fiber connector system, according to claim 2 , wherein the non-planar upstream facet of the second terminal block is an aspherical surface having an elliptical rotation effective to eliminate spherical aberrations relative to the optical axis and having the central cross section of the one aspherical surface which is described by the equation (I).