CN217467247U - Compact reflective optical fiber isolator - Google Patents

Abstract

The utility model provides a compact reflective optical fiber isolator, relating to the technical field of optical signal isolators; the method comprises the following steps: the optical fiber head comprises a first optical fiber, a second optical fiber, a half-wave plate, a collimating lens, a total reflection film and a total reflection film, wherein the first optical fiber and the second optical fiber are mutually parallelly arranged in the optical fiber head in a penetrating manner, the left side of the light splitting crystal is fixedly connected with the right side of the optical fiber head, the left side of the half-wave plate is fixedly connected with the right side of the light splitting crystal, the half-wave plate is aligned with the position of the first optical fiber, the left side of the light splitting crystal pulled by a magnetic method is aligned with the positions of the first optical fiber and the second optical fiber, the right side of the light splitting crystal pulled by the magnetic method is fixedly connected with the left side of the collimating lens, the right side surface of the collimating lens is plated with the total reflection film, and the wavelength corresponding to the total reflection film is the wavelength of a light beam emitted from the first optical fiber or the second optical fiber. The utility model has the advantages of: the existing reflector and the adjacent magnetic ring thereof are eliminated, and the defects that the reflector is inconvenient to fix in the isolator and the magnetic ring occupies the length space of the isolator are overcome; the whole structure is more compact, and the assembly is simpler.

Description

Compact reflective optical fiber isolator

Technical Field

The utility model relates to an optical signal isolator technical field specifically relates to a compact reverberation fiber isolator.

Background

The present isolator lets the light of forward transmission pass through and lets the device of reverse transmission's optical isolation, what generally adopted is transmissive structure, the device of optic fibre is all set up at present optic device's both ends, this kind is the most common optic device, the total length of this kind of optics hybrid exceeds 25 millimeters, and both ends all extend there is optic fibre, when fixed in mixing bait fiber amplifier, the optic fibre dish on both sides is fine and is taken up the volume of module great, lead to the unable reduction of volume of module, lead to holistic structure size length, it is bulky, be unfavorable for the miniaturization of device.

Patent document No. 202020686324.6 discloses a reflective isolator in 22.12.2020, and specifically discloses a reflective isolator in which a fiber head, a beam splitter crystal, a half-wave plate, a collimating lens, a faraday rotator, a mirror and a magnetic ring are sequentially arranged, so that a light beam is split into two beams through the fiber head and the beam splitter crystal, and then the two beams are reflected by the mirror, and when transmitting in the forward direction, the two beams reflected by the mirror can be combined into one beam to enter the fiber head, and when transmitting in the reverse direction, the two beams reflected by the mirror cannot be combined into one beam, and cannot enter the fiber head. The disadvantage of this solution is that the mirror and the lens are separate, and whether the relative positions of the mirror, the lens and the fiber head are stable directly affects the index requirements of the product. The fixation of the reflector is a big difficulty in the process development of the isolator; the magnetic ring is arranged on the side of the reflector far away from the Faraday rotator, and the structure is not optimized to be minimum.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in providing a compact reverberation fiber isolator, overall structure is more compact, the assembly is more simple.

The utility model discloses a realize like this: a compact reflective optical fiber isolator comprising:

the optical fiber comprises a first optical fiber, a second optical fiber, an optical fiber head, a light splitting crystal, a half-wave plate, a self-carrying magnetic pulling first optical crystal and a collimating lens;

the optical fiber head comprises a first optical fiber, a second optical fiber, a half-wave plate, a collimating lens, a total reflection film and a light beam, wherein the first optical fiber and the second optical fiber are mutually parallelly arranged in the optical fiber head in a penetrating manner, the left side of the light splitting crystal is fixedly connected with the right side of the optical fiber head, the left side of the half-wave plate is fixedly connected with the right side of the light splitting crystal, the half-wave plate is aligned to the position of the first optical fiber, the left side of the self-magnetized Faraday optical rotation crystal is aligned to the position of the first optical fiber and the position of the second optical fiber, the right side of the self-magnetized Faraday optical rotation crystal is fixedly connected with the left side of the collimating lens, the right side surface of the collimating lens is plated with the total reflection film, and the wavelength corresponding to the total reflection film is the wavelength of the light beam emitted from the first optical fiber or the second optical fiber.

Further, the wavelength corresponding to the total reflection film is 1310nm +/-30 nm or 1550nm +/-30 nm or 1590nm +/-30 nm.

Furthermore, the optical axis of the light splitting crystal is in the plane formed by the first optical fiber and the second optical fiber, and forms an included angle of 45 degrees with the central axis.

Further, the half-wave plate is a 22.5 ° half-wave plate.

Further, the self-magnetized Faraday rotator is 22.5 degrees of self-magnetized Faraday rotator.

The utility model has the advantages that: the light beam with the corresponding wavelength can enter the second optical fiber after being emitted from the first optical fiber, and the light beam with the corresponding wavelength cannot enter the first optical fiber after being emitted from the second optical fiber, so that the aim of optical signal isolation is fulfilled; the existing reflector and the adjacent magnetic ring thereof are eliminated, and the defects that the reflector is inconvenient to fix in the isolator and the magnetic ring occupies the length space of the isolator are overcome; the whole structure is more compact, and the assembly is simpler.

Drawings

The invention will be further described with reference to the following examples with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a compact reflective optical fiber isolator according to the present invention.

Fig. 2 is a schematic structural diagram of the compact reflective optical fiber isolator according to the present invention.

Reference numerals: a first optical fiber 1; a second optical fiber 2; an optical fiber head 3; a spectroscopic crystal 4; a half-wave plate 5; a Faraday rotator 6 with magnetic flux; a collimating lens 7; a total reflection film 8; a light beam 11; a light beam 12; a light beam 13; a light beam 14; a light beam 15; a light beam 16; a light beam 21; a light beam 22; a light beam 23; a light beam 24; a light beam 25.

Detailed Description

The embodiment of the utility model provides a through providing a fine isolator of compact reverberation, solved among the prior art reflector inconvenient fix in the isolator to and the magnetic ring occupies the shortcoming in isolator length space, realized that overall structure is compacter, assembles more simple technological effect.

The embodiment of the utility model provides an in technical scheme for solving above-mentioned shortcoming, the general thinking is as follows: an optical fiber head, a light splitting crystal, a half-wave plate, a self-magnetized first optical crystal and a collimating lens are arranged in sequence along the direction of an optical path; the Faraday optical rotation crystal with the magnetism is arranged on the left side of the collimating lens, a total reflection film is plated on the right side surface of the collimating lens, the wavelength corresponding to the total reflection film is the wavelength of a light beam emitted from the first optical fiber or the second optical fiber, the light beam with the corresponding wavelength can enter the second optical fiber after being emitted from the first optical fiber, and the light beam with the corresponding wavelength cannot enter the first optical fiber after being emitted from the second optical fiber, so that the aim of optical signal isolation is fulfilled.

For better understanding of the above technical solutions, the following detailed descriptions will be provided in conjunction with the drawings and the detailed description of the embodiments.

Referring to fig. 1 and 2, the preferred embodiment of the present invention.

A compact reflective optical fiber isolator comprising: the optical fiber comprises a first optical fiber 1, a second optical fiber 2, an optical fiber head 3, a light splitting crystal 4, a half-wave plate 5, a self-magnetized optical crystal 6 and a collimating lens 7; the first optical fiber 1 and the second optical fiber 2 are parallel to each other and penetrate through the optical fiber head 3, the left side of the spectroscopic crystal 4 is fixedly connected with the right side of the optical fiber head 3, the left side of the half-wave plate 5 is fixedly connected with the right side of the spectroscopic crystal 4, the half-wave plate 5 is aligned with the position of the first optical fiber 1, the left side of the self-carrying magnetic faraday optical rotation crystal 6 is aligned with the positions of the first optical fiber 1 and the second optical fiber 2, the right side of the self-carrying magnetic faraday optical rotation crystal 6 is fixedly connected with the left side of the collimating lens 7, the right side surface of the collimating lens 7 is plated with a total reflection film 8, and the wavelength corresponding to the total reflection film 8 is the wavelength of the light beam emitted from the first optical fiber 1 or the second optical fiber 2. The wavelength corresponding to the total reflection film 8 is 1310nm +/-30 nm or 1550nm +/-30 nm or 1590nm +/-30 nm. When the light beam with the corresponding wavelength is emitted to the total reflection film 8, the transmission direction of the light beam is changed.

The optical axis of the light splitting crystal 4 is in the plane formed by the first optical fiber 1 and the second optical fiber 2, and forms an included angle of 45 degrees with the central axis. The light beam emitted by the first optical fiber 1 or the second optical fiber 2 is split into two light beams with mutually vertical vibration directions after being emitted by the light splitting crystal 4, the two light beams are polarized light with fixed polarization states, one light beam is ordinary light, and the vibration direction is vertical to the plane of the optical axis; the other light beam is extraordinary light, and the vibration direction is parallel to the optical axis plane.

The half-wave plate 5 is a 22.5 deg. half-wave plate 5. I.e. the direction of the optical axis of the half-wave plate 5 is in a plane perpendicular to the direction of light propagation and at an angle of 22.5 deg. to the direction of very light vibration. After the polarized light passes through the half-wave plate 5 from left to right, the vibration directions are all rotated by 45 degrees along the optical axis of the half-wave plate 5 in the clockwise direction. After the polarized light passes through the half-wave plate 5 from right to left, the vibration directions are all rotated by 45 degrees along the optical axis of the half-wave plate 5 in the counterclockwise direction.

The Faraday rotation crystal 6 with magnetism is 22.5 degrees of Faraday rotation crystal with magnetism. After the polarized light passes through the Faraday rotator 6 with magnetism, the vibration direction is rotated by 22.5 degrees along the clockwise direction. The Faraday rotation crystal with magnetism is a mature product on the market in the field of optics. In this example, garnet crystals were used as the first optical crystal by pulling with magnetism.

The utility model discloses a compact reverberation fiber isolator's theory of operation:

(1) as shown in fig. 1, a light beam 11 enters from the left end of the first optical fiber 1 and exits from the right end of the first optical fiber 1, the wavelength of the light beam 11 is consistent with the wavelength corresponding to the total reflection film 8, after the light beam 11 enters the light splitting crystal 4, the light beam 11 is split into a light beam 12 and a light beam 13 with mutually perpendicular vibration directions, the two light beams are polarized light with fixed polarization states, one of the two light beams is ordinary light, and the vibration direction is perpendicular to the optical axis plane; the other light beam is extraordinary light, and the vibration direction is parallel to the optical axis plane. After the light beams 12 and 13 pass through the half-wave plate 5, the vibration directions are rotated by 45 degrees along the clockwise direction of the optical axis of the half-wave plate 5, and the vibration directions of the light beams 12 and 13 are still perpendicular. After the optical rotation through the half-wave plate 5, the light beam 12 and the light beam 13 enter the 22.5-degree self-magnetized crystal 6, and after the light beam 12 and the light beam 13 exit the self-magnetized crystal 6, the vibration directions are both rotated by 22.5 degrees along the clockwise direction, and the vibration directions of the light beam 12 and the light beam 13 are still vertical. The light beam 12 and the light beam 13 enter the collimating lens 7, the propagation angle changes after the light beam 12 and the light beam 13 enter the collimating lens 7 gradually, and after encountering the total reflection film 8, the light beam 12 and the light beam 13 are reflected on the right side surface of the collimating lens 7 and are respectively converted into a light beam 14 and a light beam 15. The light beam 14 and the light beam 15 enter the self-contained magnetic Faraday rotation crystal 6 after passing through the collimating lens 7 again, the vibration directions of the light beam 14 and the light beam 15 rotate by 22.5 degrees along the clockwise direction, but the vibration directions of the light beam 14 and the light beam 15 are still perpendicular to each other, and then the light beam 14 and the light beam 15 enter the light splitting crystal 4. After passing through the half-wave plate 5 and passing through the self-carrying faraday rotation crystal 6 twice, the vibration directions of the light beam 14 and the light beam 15 entering the spectroscopic crystal 4 are rotated by 90 ° compared with the vibration directions of the light beam 12 and the light beam 13 initially emitted from the spectroscopic crystal 4, but the vibration directions are still perpendicular to each other. At this time, in the spectroscopic crystal 4, the light beam 12 (ordinary light) originally emitted becomes the incident light beam 14 (ordinary light), and the light beam 13 (ordinary light) originally emitted becomes the incident light beam 15 (ordinary light), so that the light beams 14 and 15 enter the spectroscopic crystal 4, and then the light beams are recombined into one light beam 16 to be guided into the second optical fiber 2.

(2) As shown in fig. 2, a light beam 21 enters from the left end of the second optical fiber 2 and exits from the right end of the second optical fiber 2, the wavelength of the light beam 21 is consistent with the wavelength corresponding to the total reflection film 8, and the light beam passes through the light splitting crystal 4 and is split into a light beam 22 and a light beam 23 with mutually perpendicular vibration directions, both of which are polarized lights with fixed polarization states, one of which is a normal light, the vibration direction of which is perpendicular to the optical axis plane, and the other is an extraordinary light, the vibration direction of which is parallel to the optical axis plane. Then, the light beam 22 and the light beam 23 are incident on the self-magnetized faraday rotator 6, and the vibration directions of the light beam 22 and the light beam 23 are both rotated by 22.5 ° in the clockwise direction. The light beam 22 and the light beam 23 then enter the collimator lens 7, and are reflected by the total reflection film 8 on the right surface of the collimator lens 7 to be converted into a light beam 24 and a light beam 25, respectively. The light beam 24 and the light beam 25 are incident into the self-carrying magnetic Faraday rotator 6, and the vibration directions of the light beam 24 and the light beam 25 rotate by 22.5 degrees along the clockwise direction again; thus, after passing through the magneto-incorporated faraday rotator 6 twice, the vibration directions of the light beam 24 and the light beam 25 emitted from the magneto-incorporated faraday rotator 6 are rotated clockwise by 45 ° in total compared with the vibration directions of the light beam 22 and the light beam 23 emitted into the magneto-incorporated faraday rotator 6. Then the light beam 24 and the light beam 25 are incident on the half-wave plate 5, the vibration directions of the two beams of light after being emitted from the half-wave plate 5 are rotated by 45 degrees along the counterclockwise direction, that is, the rotation direction of the polarized light after passing through the half-wave plate 5 is just opposite to the rotation direction of the polarized light when passing through the self-carrying magnetic Faraday optical rotation crystal 6, so that the vibration directions of the light beam 24 and the light beam 25 obtained after the light beam 22 and the light beam 23 pass through the combination of the self-carrying magnetic Faraday optical rotation crystal 6 and the half-wave plate 5, but because the two beams of light are mutually exchanged in position after passing through the collimating lens 7, although the light beam 22 (ordinary light) emitted from the second optical fiber 2 passes through the beam splitting crystal 4, is reflected from the self-carrying magnetic Faraday optical rotation crystal 6 to the collimating lens 7, and the polarization state of the polarized light is kept unchanged when being incident on the half-wave plate 5 and the beam splitting crystal 4 again, because of the position is exchanged, the originally emitted light beam 22 (ordinary light) becomes the incident light 24 (ordinary light) in the beam 4, the original beam 23 (extraordinary light) becomes beam 25 (extraordinary light), and the two beams cannot be combined into one beam and cannot be coupled into the first optical fiber 1, so that the purpose of isolation is achieved.

The compact reflective optical fiber isolator of the utility model cancels the existing reflector and the adjacent magnetic ring thereof, overcomes the defects that the reflector is inconvenient to be fixed in the isolator and the magnetic ring occupies the length space of the isolator; the whole structure is more compact, and the assembly is simpler.

Although specific embodiments of the present invention have been described, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, and that equivalent modifications and variations can be made by those skilled in the art without departing from the spirit of the invention, which is to be limited only by the claims appended hereto.

Claims (5)

1. A compact reflective optical fiber isolator comprising:

the optical fiber comprises a first optical fiber, a second optical fiber, an optical fiber head, a light splitting crystal, a half-wave plate, a self-carrying magnetic pulling first optical crystal and a collimating lens;

the optical fiber head comprises a first optical fiber, a second optical fiber, a half-wave plate, a collimating lens, a total reflection film and a light beam, wherein the first optical fiber and the second optical fiber are mutually parallelly arranged in the optical fiber head in a penetrating manner, the left side of the light splitting crystal is fixedly connected with the right side of the optical fiber head, the left side of the half-wave plate is fixedly connected with the right side of the light splitting crystal, the half-wave plate is aligned to the position of the first optical fiber, the left side of the self-magnetized Faraday optical rotation crystal is aligned to the positions of the first optical fiber and the second optical fiber, the right side of the self-magnetized Faraday optical rotation crystal is fixedly connected with the left side of the collimating lens, the right side surface of the collimating lens is plated with the total reflection film, and the wavelength corresponding to the total reflection film is the wavelength of the light beam emitted by the first optical fiber or the second optical fiber.

2. A compact reflective optical fiber isolator according to claim 1, wherein said total reflective film corresponds to a wavelength of 1310nm ± 30nm, 1550nm ± 30nm, 1590nm ± 30 nm.

3. The compact reflective optical fiber isolator of claim 1, wherein the optical axis of said dispersing crystal is in the plane formed by said first and second optical fibers and forms an angle of 45 ° with the central axis.

4. A compact reflective optical fibre isolator according to claim 1, wherein said half-wave plate is a 22.5 ° half-wave plate.

5. A compact reflective optical fiber isolator as claimed in claim 1, wherein said self-magnetized faraday rotator is a 22.5 ° self-magnetized faraday rotator.

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