Twin-core doubly clad optical fiber two wavelength light multiplying arrangements
Technical field:
The present invention is a kind of twin-core doubly clad optical fiber two wavelength light multiplying arrangements.Be mainly used in the twin-core doubly clad optical fiber, produce the device that light signal amplifies according to controlled two wavelength of nonlinear waveguide.
Background technology:
Kang Ruide Panama plug gram in the prior art, people such as (Konrad Banaszek) goes up " the conversion and control spatial mode produces relative photon under using in the nonlinear waveguide " in the 17th phase of volume 1 day the 26th " optical communication " September calendar year 2001, discussed the device that is used to measure two-photon about conversion coherent light under the generation of nonlinear waveguide control spatial mode in (Generation of correlated photons in controlled spatialmodes by downconversion in nonlinear waveguides) literary composition.The present invention utilizes nonlinear waveguide control spatial mode to produce and changes the device that coherent light and twin-core doubly clad optical fiber realize that two wavelength light are amplified down.
Summary of the invention:
The objective of the invention is to utilize nonlinear waveguide control spatial mode to produce the principle of conversion coherent light down, a kind of twin-core doubly clad optical fiber two wavelength light multiplying arrangements are provided.
Basic thought of the present invention is:
Utilize crystal that incident light is carried out frequency multiplication, rising partially, the back is entered in the nonlinear waveguide by the guiding of microcobjective collimation, nonlinear waveguide is realized the following conversion of wavelength, separate through prism again, two wavelength are by in the concave-convex lens polymerization input coupler, coupling mechanism is coupled into two in-cores in the twin-core doubly clad optical fiber respectively with the light of two wavelength, pump light enters the middle covering of optical fiber from the side, pump light comes and goes reflection and enters respectively in two fibre cores of optical fiber in middle covering, interact with two wavelength light respectively, realize the amplification of two wavelength light.
Technical solution of the present invention is as follows:
A kind of twin-core doubly clad optical fiber two wavelength light multiplying arrangements, it is characterized in that comprising successively: lens along direction of beam propagation, frequency-doubling crystal, the plane of incidence is coated with the biconvex lens of polarizing coating, microcobjective, nonlinear waveguide, prism, concave-convex lens, coupling mechanism, the twin-core doubly clad optical fiber, also has pump laser, this pump laser is a laser diode, be positioned at the side of twin-core doubly clad optical fiber, the reception light face of described concave-convex lens is a convex surface, and be coated with anti-reflection film, its transmitted light face is a concave surface, described coupling mechanism is that skin has the fixing metal foreskin that is trapezoidal cylinder, the fixing described concave-convex lens of the big end of radius, the little end of radius is the port of twin-core doubly clad optical fiber fixedly.
Described frequency-doubling crystal can be bbo crystal, or lbo crystal, or the LDP crystal.
Described twin-core doubly clad optical fiber by two inner cores be circular, middle covering is polygon, skin is circular, the inner core refractive index is greater than the refractive index of middle covering, the refractive index of middle covering constitutes greater than the doped-glass of outer refractive index.
The advantage of apparatus of the present invention:
1. utilize nonlinear waveguide to realize Wavelength-converting down, can realize the amplification of required wavelength according to the structure of required wavelength design waveguide;
2. can be used in the integrated optics system.
Description of drawings:
Fig. 1 is the structural representation of twin-core doubly clad optical fiber two wavelength light multiplying arrangement most preferred embodiments of the present invention.
Fig. 2 is the cross sectional representation of optical fiber in the twin-core doubly clad optical fiber two wavelength light multiplying arrangements.
Among the figure:
1-lens 2-crystal 3-plating polarizing coating lens 4-micro objective
5-nonlinear waveguide 6-prism 7-concave-convex lens 8-coupling mechanism
9-twin-core doubly clad optical fiber 10-pump laser 901-twin-core doubly clad optical fiber skin
Covering 903-twin-core doubly clad optical fiber inner core in the middle of the 902-twin-core doubly clad optical fiber
Embodiment:
See also Fig. 1 earlier, Fig. 1 is the structural representation of twin-core doubly clad optical fiber two wavelength light multiplying arrangement most preferred embodiments of the present invention, as seen from the figure, twin-core doubly clad optical fiber two wavelength light multiplying arrangements of the present invention comprise: most crucial element is a twin-core doubly clad optical fiber 9, be close to coupling mechanism 8 before the twin-core doubly clad optical fiber 9, before the coupling mechanism 8 is concave-convex lens 7, before the concave-convex lens 7 is prism 6, nonlinear waveguide 5 places between microcobjective 4 and the prism 6, before the frequency-doubling crystal 2 is lens 1, be plating polarizing coating lens 3 after the frequency-doubling crystal 2, plating polarizing coating lens 3 place before the microcobjective 4.
Said lens 1 and plating polarizing coating lens 3 are that biconvex glass lens constitutes, and the left convex surface of plating polarizing coating lens 3 is coated with polarizing coating.
Said frequency-doubling crystal 2 can be a bbo crystal, or lbo crystal, or the KDP crystal.
Said microcobjective 4 is that the parallel telescope of Galileo formula constitutes.
Said nonlinear waveguide 5 is the waveguides that are coated with gallium arsenide transmission light wave on silicon base.
Said prism 6 is Tps.
Said concave-convex lens 7, its one side that receives light is a convex surface, and the one side of transmitted light is a concave surface, and convex surface is coated with anti-reflection film.
Said coupling mechanism 8 is that skin has the fixing metal foreskin, is trapezoidal cylindric, the end anchor convex lens 7 that radius is big, and the little end of radius is the port of twin-core doubly clad optical fiber 9 fixedly.
Said twin-core doubly clad optical fiber 9 is circular by two inner cores 903, middle covering 902 is polygons, and outer 901 is circular, and the inner core refractive index is greater than the refractive index of middle covering, the refractive index of middle covering constitutes greater than the doped-glass of outer refractive index, or mixes and quartzyly constitute.
Conversion coherent light and twin-core doubly clad optical fiber realized that the course of work that two wavelength light are amplified is under the present invention produced with nonlinear waveguide control spatial mode:
When incident light Is can incide on the crystal 2 after the polymerization through lens 1, after the crystal 2 frequency multiplication, former wavelength light and frequency multiplication wavelength light incide on the microcobjective 4 partially and after converging through 3 on plating polarizing coating lens simultaneously, enter into nonlinear waveguide 5 by microcobjective 4 collimation backs two wavelength light, after the nonlinear waveguide of wavelength design realizes that with the light of frequency multiplication wavelength wavelength is changed down as required, incide simultaneously on the prism 6 with former wavelength, after prism 6 beam split, the light Is and the I of two wavelength
lAgain respectively by entering respectively in optical fiber two fiber cores on the incident end face that converges to twin-core doubly clad optical fiber 9 on the concave-convex lens 7.Pump light Ip carries out pumping by the side of twin-core doubly clad optical fiber, transmission light Is and I in pump light and fiber core
lNonlinear interaction, Is and I
lBe exaggerated, by the endpiece outgoing Is ' and the I of optical fiber
l'.
In device shown in Figure 1, incident light 800nm, frequency multiplication wavelength 400nm realizes that through nonlinear waveguide Wavelength-converting is 418nm down, pump light is 360nm, power is 60mW, and the middle covering 902 of twin-core doubly clad optical fiber is an octagon, and two inner cores 903 are rounded, optical fiber is that quartzy er-doped is made, long 50 meters of optical fiber, consequently: following Wavelength-converting 418nm has been exaggerated 400 times, and former wavelength 800nm has been exaggerated 320 times.