Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/26—Optical coupling means
  • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
  • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
  • H04B10/112—Line-of-sight transmission over an extended range
  • H04B10/1123—Bidirectional transmission
  • H04B10/1125—Bidirectional transmission using a single common optical path
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
  • G02B6/421—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms the intermediate optical component consisting of a short length of fibre, e.g. fibre stub
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4246—Bidirectionally operating package structures

Definitions

• the present study aims to propose an optical space transmission device that has a simple configuration and can increase the transmission efficiency and SZN of each of transmission light and reception light.
• This device has an information transmitting light emitting element, a transmitting and receiving optical fiber, an information receiving light receiving element, a receiving optical system, and a transmission / reception common lens.
• a transmission optical fiber is provided near the focal plane of the shared lens and on the optical axis thereof, and the transmission light emitted from the information transmission light emitting element is transmitted by the transmission i optical system and The transmitting and receiving lens is transmitted to the optical space transmission path, and the received light transmitted through the optical space transmission path is made incident on the information receiving light receiving element through the transmission and reception lens and the receiving optical system.
• an optical space transmission apparatus is configured such that transmission light and reception light are spatially separated in the vicinity of a portion of a transmission optical fiber.
• the transmission / reception shared lens (3) is a transmission / reception shared lens, which is a convex lens, and uses a large-diameter, aspheric lens with small spherical aberration (for example, a diameter of 15 O mm and a focal length of 250 mm).
• the transmission / reception shared lens (3) is attached to an opening (18) formed in the other end surface of the lens barrel (1).
• (2) is a transmission / reception optical splitter, which is composed of, for example, a bundle (2A) having a diameter of about 2 mm and a bundle of a plurality of optical fibers having a diameter of about 0.1 mm. Both surfaces Tl, ⁇ 2 of the bundle (2A) form a plane perpendicular to the axial direction.
• the transmitted light (divergent light) L1 from the light emitting surface (5a) of the light emitting element (5) for transmitting optical information is converged by the transmitting lens (6), and is converged by the transmitting optical fin (7). It is incident on the end face (7 b), whereby
• the diameter D1 of the smallest circle of confusion created by the transmission / reception shared lens (3) is approximately equal to the diameter D2 of the effective light receiving surface of the bundle (2A).
• the transmission / reception shared lens (3) can be commonly used for the transmission light L1 and the reception light L2, so that the configuration is simplified. Moreover, even if the lens (3) is used for both transmission and reception, light loss due to splitting of the optical axis is extremely small. Also, fiber optic bundle
• the transmission / reception splitter (2) composed of (2A) allows the received light L2 to efficiently enter the light receiving element (9). Furthermore, the transmission light 2 can be efficiently transmitted to the optical transmission line (8) by the optical fiber (7) partially integrated with the band (2A) and the light emitting element (5). Since the degree of freedom of the arrangement with the light receiving element (9) is increased, the SZN of the transmission light L1 and the reception light L2 due to stray light can be prevented from being reduced by mutual light shielding. Furthermore, since the receiving optical axis has a certain cross-sectional area as the bundle (2A) of the optical fiber, the minimum disturbance circle of the beam narrowed down by the transmitting / receiving lens (3) is the cross-sectional area of the bundle (2A). Even if an inexpensive shared transmission / reception lens (3) having a spherical aberration that is not so small is used, the light receiving efficiency of the received light L2 can be increased.
• stray light can be reduced to 1% or less of the case where no reflection is applied to the transmission / reception shared lens (3), and further reduced if stray light is applied. Therefore, in this embodiment, it can be said that there is almost no problem with stray light.
• the cross-sectional area of the transmitting optical fiber (7) is about 1400, which is approximately the cross-sectional area of the bundle (2A), so that the transmitting optical fiber (7) of the receiving light L2 is used.
• the degree of hindrance is minimal.
• the diameter of the beam spot of the received light L2 incident on the transparent substrate (11) is about 1 mm, whereas the diameter of the protective film (13A) of the transmission optical fin (13) is small.
• the outer diameter is 0.9 mm.
• the outer diameter of the cladding is 0.125, so by removing the protective film (13A) from the transmitting optical fiber (13), the receiving light L The efficiency of incidence on the second light receiving element (9) can be greatly improved.
• the light is converged by (6), is incident on the other surface of the transmission optical fiber (13), is guided by the other surface, that is, a transparent plate,
• the transmission / reception shared lens (3) can be commonly used for the transmission light L1 and the reception light L2, so that the configuration is simplified. Moreover, even if the lens (3) is used for both transmission and reception, light loss due to photosensitivity division is extremely small. Since the degree of freedom in the arrangement of the light emitting element (5) and the light receiving element (9) is increased, the SZN of the transmission light L1 and the reception light L2 due to stray light can be prevented by mutual light shielding. . Also, the transmission and reception light should be split by the transparent plate (11). As a result, the configuration becomes simpler, and the assembling work and maintenance work of the device become easier. Further, the received light L 2 can be efficiently incident on the light receiving element (9) by the transparent plate (11). Furthermore, the transmission optical fins fitted in the through holes (11A) of the transparent plate (11)
• the transmission light L2 can be efficiently transmitted to the optical space transmission line (8).
• the transmission optical fiber (13) is fitted into the transparent hole (11A) of the transparent plate (11) to be supported.
• the present invention is not limited to this.
• a ring (21) is provided as in the third embodiment shown in FIG. Three transparent or opaque support parts (2 2) extending toward, a fitting part (2 3) is formed at the intersection, and a transmitting part is formed at the fitting part (2 3).
• the optical fiber (13) may be supported by fitting a part of the optical fiber (13).
• the transmission optical fiber (13) has a structure in which a part of the optical fiber (13) is fixed at a predetermined position, its shape and structure are not limited.
• the transmission light L 1 from the light emitting element (5) is incident on the transmission optical fin ′ (13) with sufficient energy. If the transmission lens (6) can be used, the transmission lens (6) can be omitted.
• each of the embodiments shown in FIGS. 2, 5, and 6 has the following problems.
• the lens (3) must be, for example, an aspheric lens to reduce spherical aberration.
• the parallel reception light L2 that has entered the transmission / reception shared lens (3) from the optical space transmission path (8) is focused so as to have a very small beam spot at the focal point.
• the NA of the transmitting / receiving lens (3) is required.
• the beam spot at the focal point of the received beam 1 can be made larger and the transmitted light fiber (7) or a part of (13) can be It is necessary to prevent the received light L 2 from being disturbed.
• the optical path of the optical system through which the received light L1 passes becomes longer, which leads to an increase in the size of the device.
• FIG. 7 differs from the optical space transmission device shown in Fig. 5 in that a convex lens (14) is placed between the transmission / reception shared lens (3) and the transparent lens (11). This is the point provided.
• the transmission / reception shared lens (diameter: 14.5 mm) (3) and the lens (14) are spherical lenses with small spherical aberration.
• the transmitting and receiving lenses (3), the lens (14), the transparent plate (11) and the receiving lens (4) are arranged so that the light sensitivity of the lens (3), the lens (14), and the receiving lens (4) match.
• This lens (14) is for forming a common point P2 of the focal point P1 of the transmitting / receiving lens (3).
• a transparent plate (1 1) is arranged at the conjugate point P2.
• the lenses (3) and (14) constitute a transmission / reception shared lens composed of a compound lens.
• the size of the beam spot of the received light 2 at the conjugate point P 2 is the size of the beam spot of the received light L 2 at the focal point P 1 (for example, Determine the position of the lens (14) so that its diameter is enlarged from about 100- " ⁇ ).
• the transmission optical fiber (13) for guiding the transmission light from the light-emitting element (5) to the transparent plate (11) is a single mode fiber (core diameter is 6 m, NA is 0 mm).
• the straight line of the cloud is 12 ⁇ ⁇ ⁇ .
• one surface of the portion from which the protective film (13A) has been removed is fixed to the center of the surface of the transparent plate (11) on the side of the receiving lens (4) by bonding.
• a transparent hole may be provided at the center of the transparent plate (11) and fitted there.
• the degree of interference of the reception light L 2 by the transmission optical fiber (13) is
• Transmitting light (diverging light) from the light emitting element (5) for transmitting optical information L1 is the transmitting lens
• the light is converged by (6), is incident on the other end face of the transmission optical fiber (13), is guided by the other end face, that is, its transparent surface, that is, a transparent plate.
• the light is emitted from (11) as a beam spot close to the point light source, and emitted so as to diverge toward the lens (14).
• the divergent transmitted light L 1 is converged by the lens (14), is focused at the focal point of the transmission / reception lens (3), then diverges, and enters the transmission / reception lens (3).
• the light is converted into substantially parallel light, emitted to the free space optical transmission line (8), transmitted, and received by the other free space optical transmission device.
• L 2 is incident on the receiving lens (4), is converged, and is incident on the light receiving element (9) so as to be focused. Then, the received light L2 incident on the light receiving element (9) is converted there into an electric signal.
• the transmission / reception shared lens (3) can be commonly used for the transmission light L1 and the reception light L2, so that the configuration is simplified. Moreover, even if the lens (3) is used for both transmission and reception, light loss due to splitting of the halo is extremely small.
• the focal point P i approaches the shared transmission / reception lens (3), so that the size of the apparatus can be reduced. Then, the focus of the received light L 1 is The beam spot at the point P! Is enlarged by the lens (14) and formed at the transparent plate (11) for separating transmitted and received light, and the received light L is increased by the transparent plate (11). 2 can be efficiently incident on the light receiving element (9), and the transmission light fiber 2 (13) fixed to the transparent plate (11) can efficiently transmit the transmission light L2 through the optical space transmission path. (8).

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Optical Couplings Of Light Guides (AREA)
• Optical Communication System (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=12249907

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Citations (3)

Family Cites Families (11)

• 1987
  • 1987-02-27 JP JP1987028483U patent/JPS63135322U/ja active Pending
• 1988
  • 1988-02-25 EP EP88902205A patent/EP0305534B1/en not_active Expired - Lifetime
  • 1988-02-25 WO PCT/JP1988/000198 patent/WO1988006740A1/ja active IP Right Grant
  • 1988-02-25 DE DE3887407T patent/DE3887407T2/de not_active Expired - Fee Related
  • 1988-02-25 US US07/269,661 patent/US4958902A/en not_active Expired - Fee Related
  • 1988-10-24 KR KR1019880701336A patent/KR890700841A/ko not_active Application Discontinuation

Patent Citations (3)

Non-Patent Citations (1)

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