RU2776092C1 - Optical splitter without loss on reverse reflection and with zero transmission and directivity coefficients for fiber-optic communication systems - Google Patents

Abstract

FIELD: communication technology.

SUBSTANCE: invention relates to fiber-optic splitter devices and can be used in fiber-optic networks of information exchange. The claimed optical splitter without loss on reverse reflection and with zero transmission and directivity coefficients for fiber-optic communication systems contains fiber optical guides based on quartz glass and a reflective spherical coating. The optical splitter has a spherical shape and is made of quartz glass with a refractive index n = 1.46–1.49. It consists of two parts of a sphere with flat polished surfaces with a reflective coating applied to their outer spherical surface, while each part of the sphere includes reflective mirror screens with areas that prevent radiation from the input fiber guides from interacting directly with the output fiber guides. The polished flat parts of the sphere are connected using an adhesive having the same refractive index as quartz glass, and are completely covered after gluing with the same reflective coating as reflective mirror screens. The splitter is additionally covered with a protective polymer layer.

EFFECT: ability to accurately calculate the amount of energy losses at any input or output of the splitters and, thus, provide the required uniformity of incoming and outgoing light streams due to multiple reflection of input radiation in a spherical optical splitter made of quartz glass.

1 cl, 1 dwg

Description

SUBSTANCE: invention relates to fiber-optic splitters and can be used in fiber-optic information exchange networks.

A tree splitter splits one optical signal into several outputs or performs the inverse function of combining several signals into one output. Typically, tree splitters distribute power equally to all output poles. The configuration of poles in tree splitters is denoted n x m, where n is the number of input poles, m is the number of output poles. For tree splitters, n = 1. In current tree splitters, the number m = 2 - 32. Most tree splitters are bidirectional, so they can perform signal combining functions. The transfer parameters for different output poles of the splitter tend to be closer to each other.

A star splitter usually has the same number of input and output poles. The optical signal arrives at one of the input poles and is equally distributed between all output poles. Splitters 2 x 2 and 4 x 4 are most widely used. In order to avoid confusion about the input and output poles, it is customary to designate the input poles in Latin letters, and the output numbers. Star splitters distribute the power of the optical signal equally between all optical poles.

A coupler is a generalization of a tree splitter. When the output power is not necessarily distributed equally between the output poles. Tap configurations are 1 x 2; 1 x 3; 1x4; 1x5; 1x6; 1x8; 1x16; 1 x 32. Output poles are numbered in descending order of optical power.

Splitters are characterized by the following parameters: transmission coefficient or insertion loss coefficient; directivity factor or homogeneity factor; backscatter loss.

The gain or insertion loss ratio determines the power loss of a signal that enters one of the poles and leaves one of the output poles. The transmission coefficient is determined by the ratio:

a _inc (I, j) = -10 lg (p _i,j / p _i ); db.

Indexes I, j run through the values of the numbers of input and output poles, respectively, for example i = a; j = 1

The directivity or uniformity coefficient characterizes the ability of the splitter to uniformly transfer power to the output poles. It shows the intensity of the unwanted feedback occurring at the other pole of the input pole group and is calculated using the formula:

b _dir = 10 lg (pi _,j / p _i ); db.

Indexes i , g refer to one group of poles.

Backscatter loss is the output power recorded at pole i, provided that a signal is applied to the same pole. This coefficient is similar to the return loss coefficient in optical connectors. Backscatter loss is calculated using the formula:

b _bs (i)= 10 lg (p _i,j / p _i ); db.

To represent the parameters of splitters of all types, a loss matrix is constructed. On the diagonal of the matrix are the backscatter loss coefficients, where the poles from a to 4 are sequentially selected as the input signal. For an n x n splitter, all coefficients are experimentally constructed in a 2n x 2n matrix.

Among the passive elements of fiber-optic systems, a special place is occupied by splitters, divided into categories into tree-like, star-shaped and couplers. The principles of operation of the splitters are described in the works: Ubaidullaev R.R. Fiber-optic networks. ECO-TRENDS, - M.: Radio and communication, 2001, 266 S.; Gusev A.I. Nanomaterials, nanostructures, nanotechnologies. - M.: Fizmatlit, 2007, 416 p.

The principle of operation of the proposed splitters is based on the action of the integrating sphere, described in the works: M.M. Gutorov. Fundamentals of lighting engineering and light sources. M., Energoatomizdat, 1983, 384 p. M.M. Epaneshnikov. Electric lighting, M., Energy, 1973, 352C.

A common disadvantage of known splitters is that they are characterized by energy losses determined by such parameters as transmission coefficients or insertion loss factors, as directivity or uniformity coefficients, as well as backscatter losses. The disadvantage of the prototypes is that the splitters have low reliability due to large optical losses.

Known optical splitter containing at least one bundle of quartz-polymer fibers, docked at the end with an optical mixing rod (RU 128354, IPC G02B 6/28, publ. 20.05.2013).

The disadvantage of the prototype is that the optical splitter has low reliability due to high energy losses.

The technical result lies in the fact that it allows you to clearly calculate the amount of energy loss at any input or output of the splitters and, thus, ensure the required uniformity of incoming and outgoing light fluxes, due to the multiple reflection of input radiation in a spherical optical splitter made of quartz glass.

The essence of the invention lies in the fact that an optical splitter without reverse reflection loss and with zero transmission coefficients and directivity for fiber optic communication systems contains fiber light guides based on quartz glass and a reflective spherical coating. The optical splitter has a spherical shape and is made of quartz glass with a refractive index n = 1.46 - 1.49. It consists of two parts of a sphere with flat polished surfaces and with a reflective coating applied to their outer spherical surface, while each part of the sphere includes reflective mirror screens with areas that do not allow radiation from the input optical fibers to directly interact with the output optical fibers. The polished flat parts of the sphere are connected with an adhesive having the same refractive index as quartz glass and fully coated after gluing with the same reflective coating as reflective mirror screens, and additionally coated with a protective polymer layer.

The drawing shows a diagram of an optical splitter.

The optical splitter 1 has a spherical shape. It is made of quartz glass with a refractive index n = 1.46 - 1.49 and contains input optical fibers 2 and output optical fibers 3 based on quartz glass. The optical splitter 1 consists of two parts of the sphere 4 and 5, with flat polished surfaces and with a reflective coating 6 applied to their outer spherical surface. Each flat part of the sphere 4 and 5 has reflective mirror screens 7 with areas that do not allow radiation from the input light guides 2 directly interact with the output fiber light guides 3. The polished flat parts of the sphere 4 and 5 are connected with glue having the same refractive index as quartz glass and are completely covered after gluing with the same reflective coating 6 as the reflective mirror screens 7. Additionally, the optical splitter 1 is covered with a protective polymer layer 8.

The device works as follows. The light fluxes from the input optical fibers 2 fall on the reflective mirror screens 7 in the first part of the sphere 4, which causes multiple reflections in both parts 4, 5 of the sphere and exit through the output optical fibers 3 to the consumer.

Knowing the value of the luminous flux Fe introduced into the splitter 1, it is possible to calculate the luminous fluxes output from the splitter Ф _e ¹ , determined by the area of the outlet according to the formula:

Ф _e ¹ = Fe (1-ρ) So / Sш ρ, where

Ssh - surface area of the mirror coating;

ρ is the reflection coefficient of the mirror coating;

So is the area of the outlet.

Energy losses are reduced due to multiple reflections of input radiation in a spherical optical splitter made of quartz glass.

The proposed designs of the optical splitter, for which the transmission coefficients (insertion loss coefficients), directivity coefficients (uniformity coefficients), backscatter losses lose their meaning. Input 2 and output 3 fibers are built into the optical splitter by any method of terminating optical fibers before polishing the surfaces on each spherical element.

Compared with the known solution, the proposed solution allows you to clearly calculate the amount of energy losses at any input or output of the splitters and, thus, ensure the required uniformity of incoming and outgoing light fluxes, reduces energy losses due to multiple reflections of input radiation in a spherical optical splitter made of quartz glass

Claims (1)

An optical splitter with no back reflection loss and with zero transmission coefficients and directivity for fiber optic communication systems, containing fiber light guides based on quartz glass and a reflective spherical coating, characterized in that the optical splitter, having a spherical shape, is made of quartz glass with an indicator refraction n = 1.46–1.49, consisting of two parts of a sphere with flat polished surfaces and with a reflective coating applied to their outer spherical surface, while each part of the sphere includes reflective mirror screens with areas that do not allow radiation from the input optical fibers directly interact with the output fibers, the polished flat parts of the sphere are connected with an adhesive having the same refractive index as quartz glass, and completely coated after gluing with the same reflective coating as reflective mirror screens, and additionally coated with a protective m polymer layer.

Images