CN2301801Y

CN2301801Y - Optic isolator

Info

Publication number: CN2301801Y
Application number: CN 97226586
Authority: CN
Inventors: 柳清菊; 普小云; 林理忠
Original assignee: Yunnan University YNU
Current assignee: Yunnan University YNU
Priority date: 1997-07-08
Filing date: 1997-09-25
Publication date: 1998-12-23
Anticipated expiration: 2007-09-25

Abstract

The utility model provides an optic isolator, which belongs to the field of optical instruments. The isolator changes the rising and testing deviation prisms 1, 5 with only one polarized light separating surface into four polarized light separating prisms of optical glass glued together. Three polarized light separating surfaces which are mutually parallel are provided. Thus the isolator has low forward insertion loss and the insensitivity of the polarized state of incoming rays. The input and the output of an optical fiber can be realized and the inverse isolating ratio is increased by one time. The price is cheap.

Description

A kind of optical isolator

The utility model relates to a kind of optical isolator, belongs to optical instrument field, and can be widely used in the stable laser operating state is the workplace of main purpose.

Optical isolator is a kind of passive device that allows the light one-way transmission, role is to prevent light from laser output return laser light device and its working stability is impacted again after reflection transmission course in laser system, and the key technical indexes of optical isolator is that forward inserts loss and reverse isolating ratio.Optical isolator has block type, optical-fiber type, three types of waveguide types at present.The optical isolator of wherein block type and polarization irrelevant, crystal is done, analyzer if adopt, but obtain isolation preferably, but price is more expensive, conventional polarization splitting prism is done, analyzer if adopt, though low price, isolation is lower.

The purpose of this utility model provides a kind of optical isolator, and not only forward insertion loss is low for it, and is insensitive to the polarization of incident light state, can realize the optical fiber input and output, and have high reverse isolating ratio that low price is fit to produce in enormous quantities.

The purpose of this utility model is achieved in that

This optical isolator is by the grin rod 6 of magnetic tape trailer fibre, four optical glass prisms gummed forms and constitutes the rising of three polarization light-dividing surfaces, analyzing prism 1 and 5, half-wave plate 2, magneto-optical crystal 3, magnet ring 4 is integrated, wherein rise, the prism 7 in the analyzing prism 1 and 5 and prism 11 be the isosceles triangle prism, their rib thickness long and prism 8 and prism 12 determines by needed clear aperature D.Rise, the P polarised light 10 that is parallel to each other of analyzing prism 1 and 5 outgoing and the spacing d between the S polarised light 9 be the thickness by the prism 8 of clear aperature D decision, the minimum value of d is 2D.Two such prisms respectively as rising in the optical isolator, analyzing prism 1 and 5, and are placed polarizing prism 1 between the grin rod 6 and half-wave plate 2 of magnetic tape trailer fibre, and analyzing prism 5 places between the grin rod 6 of magnet ring 4 and magnetic tape trailer fibre.Because the degree of polarization of rising of being adopted, analyzing prism 1 and 5 doubles than the degree of polarization of the polarization splitting prism that has only a polarization light-dividing surface, thereby the reverse isolating ratio of this kind isolator also will double.

Fig. 1 is the structural representation of optical isolator.

The front view that Fig. 2 has been, Amici prism is shaken in analyzing.

The left view that Fig. 3 has been, Amici prism is shaken in analyzing.

The vertical view that Fig. 4 has been, Amici prism is shaken in analyzing.

Sequence number is among the figure: 13-45 degree Brewster's angle, 14-incident light, a-prism length, b-prism width, C-prism thickness, the spacing between d-two outgoing light beams.

Technical solutions of the utility model are not limited only to shown in the accompanying drawing.

The utility model is described in further detail below in conjunction with accompanying drawing:

This optical isolator is by the grin rod 6 of magnetic tape trailer fibre, polarizing prism 1, analyzing prism 5, half-wave plate 2, magneto-optical crystal 3, magnet ring 4 is integrated, wherein, rise, analyzing prism 1 and 5 is formed by four optical glass prisms method plating multilayer dielectricity polarization beam splitter and gummed routinely, have three polarization light-dividing surfaces that are parallel to each other, cemented surface is a polarization light-dividing surface, each polarization light-dividing surface and logical light face are the Brewster's angle of 45 degree, rise, prism 7 in the analyzing prism 1 and 5 and prism 11 are the isosceles triangle prism, and their rib thickness long and prism 8 and prism 12 determines by needed clear aperature D, rise, the P polarised light 10 that is parallel to each other of inspection prism 1 and 5 outgoing and the spacing d between the S polarised light 9 are that the minimum value of d is 2D by the thickness of the prism 8 of clear aperature D decision.This, analyzing prism 1 and 5 profile be cuboid, the size of this cuboid is by clear aperature D and the P light 10 of outgoing and the spacing d decision of S light 9 of actual needs, wherein the value of prism width b and prism thickness C is determined by 2D, and the value of prism length a is determined by D+d.

In Fig. 1, rise, analyzing prism 1 and 5 quadratures.During forward transmitted, from the light of grin rod 6 outgoing of magnetic tape trailer fibre by by polarizing prism 1, half-wave plate 2, after the optically-active system that magneto-optical crystal 3 and magnet ring 4 are formed, the polarization direction has rotated 90 degree, can be fully by 5 outputs of analyzing prism, during reverse transfer, light is divided into high P light 10 of degree of polarization and S light 9 through the branch light action of analyzing prism 5, after this two bunch polarised light passes through the optically-active system equally, the polarization direction is constant, thereby can not pass through polarizing prism 1.Because reverse isolating ratio is relevant with the degree of polarization of P light 10, S light 9, degree of polarization is high more, and reverse isolating ratio is big more.Because the utility model adopted rises, analyzing prism 1 and 5 has three polarization light-dividing surfaces, the P light 10 and the S light 9 of outgoing have high-polarization, thereby reach the very high purpose of reverse isolating ratio that makes this optical isolator.

The utility model is compared with existing device of the same type, and not only the forward insertion loss is low for it, to the incident polarisation of light State is insensitive, can realize the optical fiber input and output, and reverse isolating ratio is doubled, and low price is fit to Produce in enormous quantities.

Claims

1. optical isolator by the grin rod 6 of magnetic tape trailer fibre, rises, analyzing prism 1 and 5, half-wave plate 2, magneto-optical crystal 3, magnet ring 5 is integrated, it is characterized in that, analyzing prism 1 and 5 forms by four optical glass prisms gummed, has three polarization light-dividing surfaces that are parallel to each other.

2. by the described optical isolator of claim 1, it is characterized in that, prism 7 and prism 11 in the analyzing prism 1 and 5 be the isosceles triangle prism that their rib is grown and the thickness of prism 8 and prism 12 determines by needed clear aperature D.

3. by claim 1 and 2 described optical isolators, it is characterized in that the P polarised light 10 that is parallel to each other of analyzing prism 1 and 5 outgoing and the spacing d between the S polarised light 9 are that its minimum value is 2D by the thickness of the prism 8 of clear aperature D decision.