CN1704780A - Optical wavelength division multiplexer and its optical fiber arrangement method - Google Patents

Abstract

The invention provides an optical wavelength division multiplexer and an optical fiber arrangement method thereof. After the light source of the penetration wave band is filtered by the first penetration filter wave plate, the light source of the penetration wave band can penetrate the filter wave plate for second filtering through the reflection of the optical reflector, so that the high isolation degree of adjacent wave channels is achieved; in particular, the optical fiber arrangement method of the optical wavelength division multiplexer uses the optical fiber lead to obtain the same wavelength band range of the two-time penetration filter wave plate and the minimum insertion loss of the penetration end and the reflection end by properly selecting the positions of the incident end optical fiber, the penetration end optical fiber and the reflection end optical fiber. The wavelength band ranges of the two-time penetration filtering wave plates are the same, so that the wavelength width of the wave band transmitted out through the penetration end optical fiber is not reduced due to mutual weakening after the two-time penetration filtering wave plates; the insertion loss of the transmission end and the reflection end is minimum, and the function of the optical wavelength division multiplexer can be optimized.

Description

Optical wavelength division multiplexer and its optical fiber arrangement method

technical field

The invention relates to a key basic component of a Dense Wavelength Division Multiple Task Module (DWDM) and an Optical Addition Multiple Task Module (OADM) for optical fiber communication.

Background technique

Referring to Fig. 1A, it is shown that commonly used optical wavelength division multiplexer (Optical Wavelength Division Multiplexer) 11, this optical wavelength division multiplexer is a penetrating optical wavelength division multiplexer, comprising: optical fiber lead wire 111, refractive index gradient lens 112, filter The sheet 113, the graded-index lens 119, and the fiber lead 114 are connected to each other in sequence by a bonding agent 118, and the incident-end optical fiber 115 and the reflective-end optical fiber 116 are inserted on the optical fiber lead 111, and the penetrating-end optical fiber 117 is inserted into the optical fiber on lead 114. First, the incident wavelength band passes through the optical fiber 115 at the incident end and then passes through the refractive index gradient lens 112. At this time, the incident light band enters the filter 113, and the filter 113 only allows light of one wavelength band to pass through, and the light of other wavelength bands will be reflected. , Therefore, after the incident waveband enters the filter 113, it will be divided into a penetrating waveband and a reflection waveband. The graded index lens 112 is then coupled to the reflective end optical fiber 116 . The incident waveband only passes through the filter once, and the adjacent channel isolation of the penetrating waveband generated is not very high, about 30dB.

With reference to Fig. 1 B, shown is another commonly used optical wavelength division multiplexer, and this optical wavelength division multiplexer 12 is reflective optical wavelength division multiplexer, comprises optical fiber lead wire 121, hollow spacer 122, refractive index lens 123, filter The sheet 124 and the mirror 125 are connected with each other by a bonding agent 129 . The optical fiber 126 at the incident end, the optical fiber 127 at the reflective end and the optical fiber 128 at the penetrating end are all inserted into the optical fiber lead 121 .

When the optical wavelength division multiplexer 12 is used, the incident wavebands of at least two different waveband wavelengths are introduced through one of the incident end optical fibers 126 of the optical fiber lead 121, and after passing through the graded index lens (GRIN lens) 123, one of the specific The optical signal of the wavelength band will pass through the multi-layer dielectric interference coating (multi-layer dielectric interference coating) on the filter 124, and then be reflected by the optical mirror 125, so that the light source of the penetrating wavelength band passes through the filter 124 again, and then The light is condensed by the gradient index lens 123, and then output by the penetrating end optical fiber 128 on the fiber lead 121; the optical signals of other wavelengths are reflected by the multi-layer interference coating on the filter 124, and then focused on the optical fiber by the gradient index lens 123. The lead wire is then output through the optical fiber 127 at the other reflection end.

The advantage of this architecture is that it uses a filter for two filtering mechanisms to achieve high isolation between adjacent channels, and only needs to use one lens and one fiber lead, so the volume is small.

However, in practical application, the penetrating band light source passes through the filter twice, because the incident angle is inversely proportional to the wavelength range of the penetrating band, the larger the incident angle, the shorter the penetrating wavelength range, and the smaller the incident angle, the penetrating The wavelength range is longer than the wavelength, and the transmission wavelength bandwidth after passing through the filter twice must be the same so as not to cause the wavelength width transmitted by the optical fiber at the transmission end to be too narrow for use due to mutual pinning. Therefore, when designing a reflective optical wavelength division multiplexer, attention must be paid to making the two incident angles the same; in addition, another consideration is how to minimize the insertion loss of the penetrating end and the reflecting end from the structure, and the penetrating The smaller the insertion loss of the transparent end and the reflective end, it means that the light energy lost by the light source through the component is less.

Contents of the invention

The present invention aims to solve the problem of general reflective optical wavelength division multiplexer, whether the wavelength ranges of the two penetrating bands are the same, and whether the insertion loss of the penetrating end and the reflecting end are minimal. In addition, since the reflective optical wavelength division multiplexer of the known has an oblique angle between the mirror and the filter, the conventional method is to fix the mirror and the filter with a bonding agent, and the bonding agent is likely to be damaged due to temperature changes. Expansion or contraction causes the position of the reflector to change, and this change will increase the insertion loss. The present invention aims to solve the above-mentioned problems at the same time.

The present invention utilizes a fiber pigtail (fiber pigtail), a cylindrical C-shaped lens (cylindricalshaped convex lens; C-Lens), a cap (cap) for fixing the C-shaped lens, and a filter plate with a multilayer dielectric interference coating on the surface (thin film filter), an optical mirror (HR mirror) with a reflective coating (high reflective coating) on the surface, a hollow spacer (spacer) that fixes the relative position between the lens and the fiber lead, and the spacer between the fixed filter and the optical mirror The inclined hollow gaskets with an angle α in the opposite position are bonded with adhesives between each component. The fiber lead includes a ferrule and a fiber bundle. One end of the ferrule is an inclined end, and the fiber bundle includes an incident-end fiber, a reflection-end fiber, a penetrating-end fiber and an idle fiber. The fiber bundle is inserted into the fiber lead.

Optical fiber arrangement method of the present invention:

On the ferrule end face of the fiber lead, the distance from the midpoint of the fiber core at the incident end and the fiber core at the reflective end to the fiber core at the incident end must be equal to the distance from the midpoint of the fiber core at the incident end and the fiber core at the reflective end to the wear-through The distance between the core of the optical fiber at the penetration end; the connection between the core position of the optical fiber at the penetration end and the fiber core at the reflection end must be perpendicular to the connection between the high point on the long side of the ferrule and the center point of the ferrule.

Through this arrangement of optical fibers, the incidence angles of the first penetration and the second penetration of the filter are the same, so the wavelength width of the wavelength band transmitted by the optical fiber at the penetration end will not be reduced due to mutual pinning, and The insertion loss of the reflective end and the insertion loss of the penetrating end can be coupled to the optimum value at the same time, so the insertion loss is quite small.

Through improvement of the present invention, its advantage can be summarized as follows:

The present invention utilizes an optical fiber lead wire ferrule with a square hole (square hole), which is applied to a reflective optical wavelength division multiplexer, and through appropriate selection of the common input port and the transmission output port , The position of the optical fiber at the reflection output port, it can be obtained that the incident angles of the two passes through the filter are the same, so the wavelength band ranges of the two passes through the filter are the same, so the light guided by the optical fiber at the penetration end The penetration band range is not reduced and has high adjacent channel isolation.

The present invention utilizes an optical fiber lead ferrule with a square hole and applies it to a reflective optical wavelength division multiplexer. By properly selecting the positions of the optical fibers at the incident end, the penetrating end, and the reflecting end, the optical fiber from the incident end to the penetrating end can be obtained at the same time. The insertion loss from the incident end to the reflective end can be minimized.

The present invention utilizes an inclined hollow spacer as a link between the filter and the optical mirror, because when the light source in the incident band and the light source in the reflected band are first coupled to minimize light insertion loss, it is intended to couple the light source in the incident band to the light source in the penetrating band To minimize light insertion loss, there must be an inclination angle between the filter and the optical mirror. In a general reflective optical wavelength division multiplexer, the mirror and the filter are fixed by a bonding agent, and the general bonding agent is easy to expand or contract due to temperature changes due to its large thermal expansion coefficient, resulting in a change in the angle of the optical mirror. , if the inclination angle of the mirror changes, the coupling of the penetrating band will be poor, and the optical power of the penetrating band will become lower. Therefore, the present invention uses an inclined hollow spacer as a link between the filter and the optical mirror Since the material of the hollow spacer used has a low coefficient of thermal expansion, it can greatly reduce the angle change of the optical mirror caused by the temperature change, thereby improving the optical stability.

In terms of application, it is the most economical and effective method to solve the bandwidth problem at present by modularizing multiple optical wavelength division multiplexers and applying them to optical fiber wavelength multitasking technology. Therefore, an optical adding multiplexer module with high channel isolation is required, and the performance and benefit of the optical fiber wavelength multiplexing technology will be significantly improved through the present invention.

Description of drawings

Fig. 1 is a schematic diagram showing a conventional optical wavelength division multiplexer;

Figure 2 is a combined diagram showing the present invention;

Fig. 3 is a diagram showing the optical fiber lead-through device of the present invention;

Figure 4 is a ferrule end view showing an optical fiber lead wire of the present invention;

Fig. 5 is a schematic view showing different optical fiber arrangements of the present invention;

Fig. 6 is a graph showing the light loss comparison of different optical fiber arrangements of the present invention;

Fig. 7 is a light path diagram (1) showing the present invention;

Fig. 8 is a light path diagram (2) showing the present invention;

Fig. 9 shows different embodiments of the optical fiber alignment method of the present invention;

FIG. 10 is an embodiment showing the ferrule hole patterns of different optical fiber lead wires in the optical fiber alignment method of the present invention.

in the picture

111 fiber optic lead wire 112 refractive index gradient lens

113 Filters 114 Fiber Leads

115 incident fiber 116 reflection fiber

117 Penetrating fiber 118 Bonding agent

12 Reflective Optical Wavelength Division Multiplexer 121 Fiber Leads

122 hollow gasket 123 lens

124 filter 125 reflector

126 incident fiber 127 reflection fiber

128 penetration fiber 129 bonding agent

2 optical wavelength division multiplexer 21 optical fiber leads

211 ferrule 2111 ferrule end face

2112 hole 212 fiber optic bundle

2121 Incident fiber end face 21211 Incident fiber end face

2122 reflective fiber end face 21221 reflective fiber end face

2123 Penetration fiber end face 21231 Penetration fiber end face

2124 idle fiber 213 binder

22C-shaped lens 221C-shaped lens fixing cap

23 filter 231 multi-layer dielectric interference coating

24 optical mirrors 241 reflective coating

25 Hollow Gasket 26 Inclined Hollow Gasket

A high point C fiber core at the input end

I Incident Band J Reflection Band

K penetration band

O The midpoint of the distance between the fiber core at the incident end and the fiber core at the reflection end

P penetration fiber core

R reflective fiber core

Center point of T ring

Detailed ways

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

With reference to Fig. 2, shown is the combination diagram of the present invention, and this optical wavelength division multiplexer 2 comprises:

An optical fiber lead 21, a cylindrical C-shaped lens 22, a C-shaped lens fixed cap (cap) 221, a filter 23 with a multilayer dielectric interference coating 231 on the surface, and an optical mirror 24 with a reflective coating 241 on the surface , the hollow gasket 25 between the fixed lens and the relative position of the optical fiber lead 21, the relative position between the fixed filter 23 and the optical mirror 24 and an inclined hollow gasket 26 (spacer) with an angle α, the optical fiber lead 21 includes A ferrule 211 and an optical fiber bundle 212 are provided. The fiber bundle 212 includes an incident-end optical fiber 2121 , a reflection-end optical fiber 2122 , and a penetration-end optical fiber 2123 .

The above-mentioned C-shaped lens 22 can also be replaced by other lenses with focusing effect, such as aspheric lens (aspheric lens).

All components are bonded with adhesive 213, which is not shown in the drawing. The ferrule 211 of the optical fiber lead wire 21 and one end of the C-shaped lens 22 are all processed to have a surface with an angle of 8 degrees relative to the YOX plane. When the lens 22 is used, a small part of the reflected light will return to the original incident optical fiber through the original path, causing signal interference of the light source.

Generally, the diameter of the fiber cladding of a single mode fiber is 125 μm, and the diameter of the fiber core is 8.3 μm. Please refer to FIG. 3 and FIG. 4 , which show the diagram of the fiber lead device and the ferrule end view of the fiber lead of the present invention, which are made by using a ferrule 211 with a square hole. The end face has an angle of 8 degrees. The shape of the hole in the ferrule can also be rectangular or other shapes to accommodate the fiber bundle 212. The fiber bundle 212 includes an incident-end optical fiber 2121, a reflection-end optical fiber 2122, a penetration-end optical fiber 2123 and an idle optical fiber 2124. The above-mentioned optical fibers are inserted into the optical fiber lead 21 , and form different end faces on the end face 2111 of the ferrule, which are the fiber end face 21211 at the incident end, the fiber end face 21221 at the reflection end, and the fiber end face 21231 at the penetrating end. When the core C, the fiber core R at the reflection end and the fiber core P at the penetration end are inserted into the central square hole 2112 of the ferrule 211 , each fiber is fixed with a bonding agent 213 .

In use, the idle optical fiber 2124 is not used for transmitting or receiving optical signals, so the optical fiber at its rear end will be cut off.

Please refer to FIG. 2, FIG. 3 and FIG. 4, when the optical wavelength division multiplexer 2 is in operation, at least two optical signals I (such as λ1, λ2, λ3) of different wavelength bands enter from the incident fiber 2121, meaning That is, the light will emerge from the fiber core C of the fiber at the fiber at the fiber end face 21211 at the fiber at the fiber at the fiber at the fiber, after passing through the C-shaped lens 22, it will not be the light that the multilayer dielectric interference coating 231 on the filter 23 can penetrate (such as λ2, λ3 ), is reflected by the filter 23, and then focused on the position of the core R of the reflective fiber end face 21221 of the reflective fiber end face 21221 through the C-shaped lens 22, and guided out by the reflective fiber 2122.

The wavelength (such as λ1) that can be filtered by the multilayer dielectric interference coating 231 on the filter 23 reaches the optical mirror 24 behind it after passing through the filter 23, and the reflective coating 241 on this optical mirror 24 will The light in this wavelength band is reflected back to the filter 23 for the second filtering and penetration, and then is focused on the position of the core P of the penetrating-end optical fiber end face 21231 by the C-shaped lens 22. 2123 leads out, and this penetrating wavelength (λ1) undergoes two filtering actions.

Compared with the optical signal filtered once, the wavelength range of the optical signal filtered twice has a higher adjacent channel isolation, which can reach more than 50dB.

Since the four optical fibers are closely arranged in the square hole 2112 of the ferrule 211, the relative positions of the four optical fibers can be fixed on the four corners of the hole and arranged closely, so the distance between the two and the relative angle are fixed. Yes, the optical fiber is fixed in the ferrule 211 by using the bonding agent 213, so the optical fiber will not be loosened. Since one end of the ferrule 211 has a slanted end at an angle of 8 degrees, if point A is defined as point A on the longest side of the slanted end of the ferrule 211, point A is defined above the square hole 2112 in FIG. 4 . In this embodiment The optical fiber configuration on the fiber lead wire 21 described is as follows: the fiber core C at the incident end is at the lower left of the square hole 2112, the fiber core R at the reflection end is at the upper right of the square hole 2112, and the fiber core P at the penetrating end is at the square hole 2112. The upper left of the hole 2112, and the idle fiber 2124 is at the lower right of the square hole 2112; the purpose of this arrangement is to make the connection between the core position P of the penetrating end optical fiber 2123 and the core position R of the reflecting end optical fiber 2122, and The line between the high point A on the long side of the ferrule 211 and the center point T of the ferrule is perpendicular to each other. Because when the reflected waveband J (such as λ2, λ3) and the penetrating waveband K (such as λ1) are reflected by the filter 23 and the optical reflector 24 and must be focused on the hole 2112 of the ferrule 211 through the C-shaped lens 22, this When the beam behavior is converging, the fiber core R at the reflective end and the optical fiber core P at the penetrating end must be located at the same position behind the C-shaped lens 22 at the same time, and this position is approximately near the focus point. , to obtain the best light source coupling at the penetrating end and reflecting end at the same time, so if the core position P of the penetrating end fiber 2123 is connected to the core position R of the reflecting end optical fiber 2122, the high point on the long side of the ferrule 211 The connection between A and the center point T of the ferrule is perpendicular to each other, then the light source in the reflection band J and the light source in the transmission band K travel the same distance in the lens, and we can simultaneously obtain the fiber end face 21221 at the reflection end and the fiber end face 21231 at the transmission end relative to C The shape lens 22 is focused on the optimal distance at the same time, so the insertion loss of the reflective end and the penetrating end can reach the minimum value at the same time.

In addition, for the penetration band K (such as λ1), the incident angle (incident angle) when the penetration band K penetrates the filter 23 for the first time, and the incident angle when the penetration band K penetrates the filter 23 for the second time must be the same; because the incident angle affects the wavelength range of the transmitted light, if the incident angle is larger, the wavelength range of the transmitted light is shorter than the wavelength band, and if the incident angle is small, the wavelength range of the transmitted light is longer than the wavelength band, if the first If the incident angles of the first-time transmitted light and the second-time transmitted light are different, the width of the waveband range after the two times of transmission through the filter 23 will weaken each other and be too narrow to be used.

Therefore, in order to comply with the same incident angle during the two penetrations, in the optical fiber arrangement method of the present invention, the relative positions of the incident-end optical fiber 2121, the reflection-end optical fiber 2122, and the penetration-end optical fiber 2123 on the ferrule end face 2111 are:

On the ferrule end face 2111 of the optical fiber lead 21, the distance from the midpoint O of the fiber core C at the incident end and the fiber core R at the reflection end to the fiber core C at the entrance end must be equal to the fiber core C at the incident end and the fiber core C at the reflection end The distance from the midpoint O of the fiber core R to the fiber core P at the penetration end, that is, the CO distance must be equal to the PO distance. Through this arrangement, the incident angles of the first penetration and the second penetration are the same, so the waveband ranges after the two passes through the filter 23 are the same, so the width of the waveband range will not be weakened by each other.

To sum up, the arrangement of optical fibers to make the wavelength ranges after passing through the filter 23 twice the same, and to minimize the insertion loss of the reflection end and the penetration end is as follows:

On the ferrule end face 2111 of the optical fiber lead 21, the distance from the midpoint O of the fiber core C at the incident end and the fiber core R at the reflection end to the fiber core C at the entrance end must be equal to the fiber core C at the incident end and the fiber core C at the reflection end The distance from the midpoint O of the fiber core R to the fiber core P at the penetration end. The connection between the fiber core P at the penetration end and the fiber core R at the reflection end is perpendicular to the connection between the high point A on the long side of the ferrule 211 and the center point T of the ferrule.

Please refer to Fig. 5, which shows the arrangement mode of the hole shapes in different fiber lead ferrules to the optical fiber, we define that the high point A on the ferrule 211 long side of the fiber lead 21 is at the top of the figure; in Fig. 5A The shape of the hole 2112 of the ferrule 211 is a square that can accommodate four optical fibers. When the positions of the fiber core C at the incident end, the fiber core P at the penetrating end, and the fiber core R at the reflection end are different from the arrangement positions in FIG. 3 , Although the distance of CO is equal to the distance of PO, that is, the incident angles during the first penetration and the second penetration are the same; however, due to the connection between the fiber core P at the penetration end and the fiber core R at the reflection end, there is no connection with the fiber core R at the reflection end. The connection between the high point A on the long side of the ferrule and the central point T of the ferrule is perpendicular to each other, which means that the optical fiber core R at the reflection end and the optical fiber core P at the penetrating end converge light at different positions on the C-shaped lens 22, and the reflection band The J light source and the penetrating band K light source travel different distances in the C-shaped lens 22, so when the reflective end is coupled to the minimum insertion loss, the penetrating end cannot be coupled to the optimum value, and the penetrating end and the reflective end cannot be coupled to The optimum value, so the insertion loss at the penetration end is relatively large.

The shape of the hole 2112 of the ferrule in Figure 5B is an equilateral triangle hole that can accommodate three optical fibers, the shape of the hole 2112 of the ferrule in Figure 5C is a long row of holes that can accommodate three optical fibers, the fiber bundles on these two ferrules 211 212 is arranged at the position of the hole 2112. When applied to the optical structure of our optical wavelength division multiplexer 2, the connection between the fiber core R of the reflection end fiber 272 and the fiber core P position of the penetration end fiber 273 is not related to The connection between the high point A on the long side of the ferrule 211 and the center point T of the ferrule is perpendicular to each other, so that the penetration end and the reflection end cannot be coupled to the optimal value at the same time, resulting in high insertion loss; the other is the distance of CO and PO The distances are not the same, and the incident angles when the penetration band K passes through the filter 23 for the first time and the second time through the filter 23 will not be the same, which causes the problem that the width of the band range is too narrow to be usable. Therefore, the arrangement of these optical fiber holes 2112 in FIG. 5 is not the best choice.

Please refer to FIG. 6 , which shows the comparison of angle difference and light loss between the optical fiber arrangement of the present invention and other different optical fiber arrangements when passing through the filter twice, which is a supplementary description of FIG. 5 . First explain the arrangement of the optical fibers in this figure. The high point A of the ferrule 211 is defined at the top of the figure. It can be seen from the figure that if the arrangement of the optical fibers in the ferrule 211 is a long row of holes or a triangle When the hole shape is used, the angle difference Δα between the first incident and the second incident is 3.67 degrees and 1.34 degrees respectively. This angle difference makes the band ranges different when the filter 23 is penetrated twice, reducing the overall penetration at the penetration end. The width of the waveband range that the optical fiber 2123 exits; in addition, because of the connection between the point P of the fiber core of the penetrating end and the point R of the fiber core of the reflection end, there is no relationship with the high point A on the long side of the ferrule 211 and the center point T of the ferrule. The lines are perpendicular to each other, so that when the reflective end is coupled to the optimal insertion loss, the difference ΔIL between the insertion loss of the penetrating end and the optimal value is 0.25dB and 0.10dB respectively; in addition, if the optical fibers are arranged in a square in the ferrule 211 , as shown in the third arrangement in Figure 6, if it does not conform to the arrangement of the present invention, although the distance from the fiber core C at the incident end to the midpoint O as shown in the figure is equal to the distance from the fiber core P at the penetration end point O, but the connection between point P of the fiber core at the penetration end and point R at the reflection end is not perpendicular to the connection between the high point A on the long side of the ferrule 211 and the center point T of the ferrule, so The reflective end and the penetrating end cannot be in the optimal coupling state at the same time, resulting in an additional high insertion loss, and the difference ΔIL between the insertion loss of the penetrating end and the optimal value is 0.25dB; if the optical fiber is arranged in the ferrule 211 as In the case of a square, and according to the optical fiber arrangement of the present invention, Δα is 0, and ΔIL is also 0, which means that the optical fiber arrangement of the present invention is quite good in use.

According to the optical fiber position arrangement in Figure 4, when assembling the optical wavelength division multiplexer 2 as shown in Figure 2, after the light source of the incident band I enters the optical fiber 2121 at the incident end, the insertion loss of the light source of the reflected band J is coupled first, and when the light source of the reflected band When the insertion loss of J is coupled to the minimum value, first fix the relative positions of the filter 23, the C-shaped lens 22 and the fiber lead 21 with a bonding agent 213, and then couple the light source of the penetrating band K to the penetrating end optical fiber 2123, at this time, to be able to couple the penetrating band K to the penetrating end optical fiber 2123, the optical reflector 24 must be inclined at a fixed angle α, the degree of this inclination angle depends on the arrangement of the optical fibers and the type of lens used Depending on the lens parameters, the angle α can range from 0.5° to 4.0°. When tilting this angle, the light source of the penetrating band K can be guided into the fiber core P at the penetrating end, and the minimum insertion loss at the penetrating end can be obtained.

Please refer to FIG. 7 and FIG. 8 , which show the light path diagram (1) and the light path diagram (2) of the present invention, and the light path diagram (2) is another perspective of the light path diagram (1). When the incident waveband I (such as λ1, λ2, λ3) is incident on the filter 23, the penetrating waveband K (such as λ1) passes through the interference coating 231 on the filter 23 once, and then is reflected on the reflective coating 241 of the optical mirror 24 , and then pass through the interference coating of the filter 23 once, and the reflection band J (such as λ2, λ3) is a wave band that cannot pass through the interference coating 231 on the filter 23, and is reflected by the interference coating 231.

The inclined hollow gasket 26 in the figure is a gasket ring with an angle α. The material of the gasket should be selected with a thermal expansion coefficient as small as possible, which can be between 0×10-6/°C and 25×10-6/°C to avoid the influence of temperature changes. Figure 7 and Figure 8 are the top view (if defined by the card coordinates as the view viewed from the origin to the +Y direction) and the front view (if defined by the card coordinates as the view viewed from the +X direction to the origin) ), from the direction of Figure 7, you can see the angle α of the inclined hollow spacer 26 in the figure; Epoxy) type binder 213 is used for bonding, because the thermal expansion coefficient (thermal expansion coefficient) of the general binder 213 is very large, so the performance of the product (performance), the sensitivity of the insertion loss to temperature will be Therefore, we choose to utilize an inclined hollow spacer 26 with angle α and its thermal expansion coefficient is small, and its thickness is not very thick, and the light waist (beam waist) position is set on the filter plate 23 during assembly. In the middle of the multilayer dielectric interference coating 231 and the high reflection coating 241 on the optical mirror 24, this is because the incident waveband I is incident from the fiber core C at the incident end, and the position of the fiber core C at the incident end is close to that of a C-shaped lens 22, after the incident waveband I passes through the C-shaped lens 22, the light source is projected on the filter 23 and the optical mirror 24 in a form similar to parallel light. When the dielectric interference coating 231 is placed on the light waist, the best insertion loss of the reflective end can be obtained by coupling; if the reflective coating 241 on the optical mirror 24 is placed on the light waist, the best insertion loss of the penetrating end can be obtained loss. However, since the light source here is in the form of parallel light, no matter the positional deviation of the multi-layer dielectric interference coating 231 or the reflective coating 241 on the OZ axis has little effect on the insertion loss, so the The insertion loss of the penetration end and the reflection end has little influence. In addition, because the thermal expansion coefficient of the angled hollow spacer 26 is very small, the angle between the filter 23 and the optical mirror 24 will not change too much when the temperature changes, and the sensitivity of the insertion loss to temperature can be quite small. .

Please refer to Fig. 9, A, B, C and D in Fig. 9 are different optical fiber arrangements on the ferrule end face 2111 of the optical fiber lead wire 21, wherein the high point A of the ferrule 211 is schematically shown at the top of the figure, and can be seen in the figure to different embodiments of the optical fiber alignment method consistent with the present invention.

It should also be noted that when using different optical fiber leads 21, as long as the shape and size of the central hole 2112 of the ferrule 211 of the optical fiber lead 21 are sufficient to accommodate The positions of the three optical fibers are equal to the optical fiber arrangement described in the present invention, and can also be applied to the implementation scope of the present invention.

Please refer to FIG. 10 , which shows the shape and size of the ferrule 211 central hole 2112 of different optical fiber lead wires 21 to accommodate different embodiments including at least an incident-end optical fiber 2121, a reflection-end optical fiber 2122 and a penetration-end optical fiber 2123, as shown in FIG. 10A The shape of the hole 2112 of the ferrule 211 is a double rectangle. The shape of the hole 2112 of the ferrule 211 of FIG. 10B is oval. The shape of the hole 2112 of the ferrule 211 of FIG. Triangular, the shape of the hole 2112 of the ferrule 211 in Fig. 10E is double oval.

It can be seen from FIG. 10 that the types of holes 2112 of different ferrules 211 can be applied to the optical wavelength division multiplexer 2 of the present invention as long as they can conform to the optical fiber arrangement method of the present invention. There are many permutations not listed.

The above description has analyzed the characteristics of some optical components of the optical wavelength division multiplexer 2, including the arrangement of the optical fibers in the optical fiber lead 21, and the behavior of the transmission band I and the reflection band J in the optical addition filter 2, There is also an inclined hollow spacer 26 with an angle α inserted between the filter plate 23 and the optical mirror 24 to improve product performance. However, the above descriptions are only used to explain the preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Therefore, any modification or change related to the present invention made under the same creative spirit is covered by the patent scope of the present invention.

Claims (9)

1. light wavelength division multiplexing is characterized in that optical device comprises:

One fiber-optic wire comprises lasso and fibre bundle;

This lasso one end has the end face at angle of inclination;

The beveled end of this lasso connects a hollow pad, and this hollow pad other end connects lens;

The other end at described lens connects a filter plate through lens locking cap cover;

This filter plate other end connects inclination hollow pad, and this inclination hollow pad connects an optical mirror again;

The fibre bundle of this fiber-optic wire comprises incident end optical fiber, penetration end optical fiber and reflection end optical fiber at least, and this fibre bundle inserts described lasso and fixes, and described each optical fiber inserts the position of lasso, is seen as from ring face:

The mid point of fine nuclear of incident end optical fiber and the fine nuclear of reflection end optical fiber equals the distance of the mid point of fine nuclear of incident end optical fiber and the fine nuclear of reflection end optical fiber to the fine nuclear of penetration end optical fiber to the distance of the fine nuclear of incident end optical fiber;

The fine nuclear location of penetration end optical fiber and reflection end optical fiber online, online mutual vertical with height point on the long limit of lasso and lasso central point.

2. light wavelength division multiplexing according to claim 1 is characterized in that:

Wherein the central authorities of the employed lasso of this fiber-optic wire establish a hole, and this hole is a square, and square aperture hollow scope wherein only can be held 4 optical fiber.

3. light wavelength division multiplexing according to claim 2 is characterized in that:

The central authorities of the lasso of this fiber-optic wire establish a hole, and this hole system is a kind of by circle, rectangle, ellipse, two rectangle, two avette or group that triangle is formed, and the described hole size is enough to hold three above optical fiber.

4. light wavelength division multiplexing according to claim 1 is characterized in that:

These lens are column C type lens.

5. light wavelength division multiplexing according to claim 1 is characterized in that:

These lens are non-spherical lens.

6. light wavelength division multiplexing according to claim 1 is characterized in that:

The suitable optical wavelength range of this optical mirror 500nm to 1800nm between.

7. light wavelength division multiplexing according to claim 1 is characterized in that:

Two planes of this inclination hollow pad, a plane has the angle of an inclination, and the angular range of inclination is spent between 4.0 degree 0.5.

8. according to claim 1 or 7 described light wavelength division multiplexings, it is characterized in that:

This inclination hollow pad thermal expansivity scope is between 0 * 10-6/ ℃ to 25 * 10-6/ ℃.

9. the optical fiber arrangements method of the fiber-optic wire of a light wavelength division multiplexing, fibre bundle inserts in the lasso of fiber-optic wire, and this fibre bundle comprises incident end optical fiber, penetration end optical fiber and reflection end optical fiber at least, from the ranking method of this fibre bundle of ring face is:

The mid point of fine nuclear of incident end optical fiber and the fine nuclear of reflection end optical fiber need equal the distance of the mid point of fine nuclear of incident end optical fiber and the fine nuclear of reflection end optical fiber to the fine nuclear of penetration end optical fiber to the distance of the fine nuclear of incident end optical fiber;

The fine nuclear location of penetration end optical fiber and reflection end optical fiber online, online mutual vertical with height point on the long limit of lasso and lasso central point.

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