CN1068895A

CN1068895A - A kind of optical isolator

Info

Publication number: CN1068895A
Application number: CN 91105179
Authority: CN
Inventors: 周密; 黄德修
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 1991-07-23
Filing date: 1991-07-23
Publication date: 1993-02-10
Anticipated expiration: 2006-07-23
Also published as: CN1026363C

Abstract

This optical isolator is a kind of passive device, and it is by pair of parallel quadrilateral polarization splitting prism, faraday optical rotation components and an end mirror is set behind analyzer constitutes, and can make the isolation ratio multiplication to three multiplications.

Description

A kind of optical isolator

The invention belongs to optical passive component.

" with the optical isolator of polarization irrelevant " (HUST that China's " laser and infrared " delivered 2 phases in 1991, carefully, Liu Deming, a Huang Dexiu) civilian disclosed optical isolator, though broken general in the world, adopt in optical isolator that kalzit rises, analyzer pass through example, and replace with polarization splitting prism, expensive calcite crystal is made, the shortcoming of analyzer thereby avoid using, but this structure can't reach two multiplications or three times of isolation ratios that increase common isolator.

The purpose of this invention is to provide a kind of optical isolator that makes the isolation ratio multiplication.

For achieving the above object, the present invention takes following technical measures: employing pair of parallel quadrilateral polarization splitting prism substitutes, analyzer, in the middle of them, faraday is set and executes optical element, 2 ports are provided with end mirror behind analyzer, by rise, the branch of analyzer, the reflection effect of closing light action and end mirror, reach two multiplications or three times of isolation ratios that increase common isolators.As shown in Figure 1, I, II are polarization splitting prism, it between them the faraday optical rotation components III, because the polarization spectro characteristic of I, II, the incident light of random polarization state is through the reverse incident of 1 port and will be divided into the orthogonal two-beam in polarization direction behind the I prism, this two-beam after 1 mistake faraday optical rotation components changes light action, closes light and retrodeviates out buffer action of light path formation respectively at second polarization splitting prism II place, its leak light goes out from 2 end-fires.When it when the reverse incident of fresh warp thread II prism is laid equal stress in end mirror A reflection, same principle will deflect away from light path 3 ports after the two-beam after leak light is decomposed will close light at I prism place once more, reach the isolation ratio that twice increases common isolator.If want three times to increase isolation ratio, it installs as shown in Figure 2, sets up end mirror B at front 3 ports that play inclined to one side Amici prism I, and the leak light after the secondary isolation is closed light through the reflection back at II prism place and retrodeviated out light path (4 port)

Fig. 1 is the schematic diagram of two multiplication optoisolators.

Fig. 2 is the schematic diagram of three multiplication optoisolators.

Advantage of the present invention is a lot, is mainly manifested in:

1. need not to increase shielding system behind the employing end mirror can reach isolation ratio two multiplications of common isolator or the effect of three multiplications. Because the forward insertion loss of shielding system is very low, but reverse isolating ratio is very high, this multiplication has greatly improved the performance of isolator.

2. only need be by adjusting low-angle method of end mirror inclination, the leak light that can avoid light to produce in the reflection process back and forth by catoptron is coupled to the situation that each port of isolator causes isolation ratio to descend again.

3. by adjusting the forward angle of rotation that position and faraday optical rotation components are set of polarization splitting prism I, II, can adjust the order of isolator output port and the position of catoptron easily, for processing brings very big facility.

4. owing to adopt parallelogram polarization dispersion prism, isolator all is suitable for the incident light of random polarization state.

Parallelogram polarization dispersion prism as rise, the analyzing element, make isolator form a plurality of input/output port, thereby adopt this basic structure can form the series of products of isolator.

6. parallelogram polarization dispersion prism can be made of calcite crystal or simple glass, when adopting simple glass to make, forms polarization beam splitter by being coated with multilayer dielectric film at its cemented surface, and this method is applicable to large-scale production, and cheap.

7. by the reflection of adjusting multilayered medium polarization beam splitter and the position of transmission band, isolator is applicable to different logical optical bands.

8. by adjusting the optimized incidence of polarization beam splitter, can directly be coated with reflectance coating and replace catoptron with simplified structure in the polarization spectroscope relevant position.

9. parallelogram polarization dispersion prism also can be made into the square polarization splitting prism, is convenient to directly be coated with reflectance coating.

10. the input of isolator, output port can use the grin rod of magnetic tape trailer fibre to coupling, thereby realize the optical fiber input of optoisolator.

Claims

1, a kind of optical isolator, it is made of pair of parallel quadrilateral polarization splitting prism and faraday optical rotation components, it is characterized by an end mirror (A) is set behind polarization splitting prism (II).