JP3888682B2 - Surface type optical semiconductor module with fiber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the structure of an inexpensive module with a fiber such as a surface optical semiconductor device, particularly a surface emitting semiconductor laser, and more particularly to the structure of an inexpensive and wavelength-tunable surface emitting semiconductor laser module with a fiber.
[0002]
[Prior art]
Various techniques have been established for semiconductor laser modules in which electrodes are attached to a semiconductor laser chip and light is coupled to an optical fiber, mainly for communication, and mass production techniques have been achieved.
[0003]
There are various methods for using a semiconductor laser as a module with a fiber, and a typical structure is shown in FIG. In FIG. 18, 1 is a stripe laser chip (waveguide semiconductor laser chip), 2 is a ball lens, 3 is a semiconductor laser mount, 4 is an electrode formed on the semiconductor laser mount 3, 5 is an isolator, and 6 is an optical fiber. is there.
The waveguide type semiconductor laser chip 1 is mounted on the semiconductor laser mount 3 by soldering, the ball lens 2 is fixed to both sides of the waveguide type semiconductor laser chip 1 with an adhesive, and if necessary, an isolator 5 is mounted. To do. Then, while emitting light from the waveguide type semiconductor laser chip 1, the optical fiber 6 is aligned and fixed by an adhesive or YAG laser welding. (For example, see Non-Patent Document 1)
[0004]
[Non-Patent Document 1]
JUAN SEPULVEDA AND LISA VALENZUELA, "integrated subassemblies improve optoelectronic package performance", Optical Manufacturing, USA, May2002, p.27-29
[0005]
[Problems to be solved by the invention]
Thus, conventionally, since so-called active alignment is performed, time and labor for this alignment are required. Therefore, even if the semiconductor laser laser chip 1 is low in price, the price of the module with the fiber must be high. It was.
[0006]
The waveguide type semiconductor laser chip 1 is very difficult to handle because it is very small, a few hundred μm square, and it is very difficult to solder with accurate positioning and orientation when mounting, with human eyes and hands. Labor is required because alignment is required. Further, in the waveguide type semiconductor laser chip 1, since the outgoing beam is greatly spread, the ball lens 2 is necessary, and since the beam is flat, the coupling loss is very large. Furthermore, since the diameter of the core of the optical fiber 6 is as small as 10 μm, the alignment needs to be adjusted in a total of five axes, ie, three axes and two axes. By using robots, we are trying to reduce costs by reducing human resources as much as possible, but the price of semiconductor laser module equipment becomes expensive, and the cost of semiconductor laser modules can not be reduced unless a considerable amount is mass-produced. is the current situation.
[0007]
On the other hand, if the semiconductor laser module is manufactured, if the semiconductor laser and the optical fiber can be passively aligned without emitting the semiconductor laser, the cost of the module can be greatly reduced. In other words, if the semiconductor laser module can be formed so as to fit the block, the semiconductor laser module is significantly reduced in cost. In addition, surface detectors with narrow light-receiving surfaces still require alignment with optical fibers and are cheaper than laser modules, but they still have the drawback of requiring labor in module assembly and increasing costs. It was.
[0008]
On the other hand, the use of surface-emitting semiconductor lasers instead of waveguide-type semiconductor laser chips is currently being studied. Since the surface emitting semiconductor laser has a circular emission light and a small beam divergence angle, the surface emitting semiconductor laser and the optical fiber are brought close to each other, and the light from the surface emitting semiconductor laser is emitted by a butt joint without using a lens. It is said that an inexpensive module with a fiber that can be coupled to a fiber can be realized. However, since the alignment of the optical fiber and the surface emitting semiconductor laser is currently performed by active alignment, the price has not actually been reduced.
[0009]
Therefore, in view of the above circumstances, an object of the present invention is to provide an inexpensive surface-type optical semiconductor module with a fiber capable of passive alignment of optical fibers.
[0011]
[Means for Solving the Problems]
  <Protrusions are formed by combining ferrules with different diameters>
  Solve the above issuesFirst1The surface optical semiconductor module with a fiber according to the present invention is a surface optical semiconductor device that emits light, receives light or inputs / outputs light perpendicularly to the surface of a semiconductor wafer, such as a surface emitting semiconductor laser, a photodiode, a surface optical amplifier, and a surface optical gate. In a module in which an optical fiber is connected to
  On the surface on the epitaxial layer side or the back surface on the semiconductor substrate side of the planar optical semiconductor device, for alignment located on the circumference centered on the light emitting part, the light receiving part or the optical input / output part of the planar optical semiconductor device Forming protrusions or grooves,
  And using the 1st ferrule and the small piece of the 2nd ferrule whose diameter is smaller than this 1st ferrule, the small piece of the 2nd ferrule is said 1st on the one end surface of the 1st ferrule. A protrusion located on the circumference centering on the central axis of the first ferrule is formed by bonding the central axis of the ferrule and the central axis of the small piece of the second ferrule in an aligned state. And
  The surface of the planar optical semiconductor device having the projection or groove formed thereon is opposed to the surface of the first ferrule projection, and the projection or groove of the planar optical semiconductor device and the projection of the ferrule Are arranged so that the light emitting part, the light receiving part or the light input / output part of the planar optical semiconductor device is at the center of the first ferrule, and the optical fiber is inserted into the ferrule. ,
  By passively aligning the center of the light emitting unit, the light receiving unit or the light input / output unit of the planar optical semiconductor device and the center of the optical fiber, the light emitting unit, the light receiving unit or the light of the planar optical semiconductor device. The optical input / output unit and the optical fiber can be optically coupled.
[0012]
  <Direct processing of planar optical semiconductor devices>
  The second2The surface-type optical semiconductor module with fiber of the invention is the first module.MysteriousIn a surface type optical semiconductor module with fiber,
  A protrusion or groove for alignment formed on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device,
  The surface optical semiconductor device is formed by being directly processed by a technique such as etching on the epitaxial layer side surface or the semiconductor substrate side rear surface.
[0013]
  <Coating a surface optical semiconductor device with a layer of another material and processing it>
  The second3The surface-type optical semiconductor module with fiber of the invention is the first module.MysteriousIn a surface type optical semiconductor module with fiber,
  A protrusion or groove for alignment formed on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device,
  An insulating layer made of polyimide or the like provided on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device is formed by a technique such as etching.
[0014]
  <Processing after bonding another substrate to a planar optical semiconductor device>
  The second4The surface-type optical semiconductor module with fiber of the invention is the first module.MysteriousIn a surface type optical semiconductor module with fiber,
  A protrusion or groove for alignment formed on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device,
  It is characterized in that it is formed by processing another semiconductor or glass substrate bonded directly or via an adhesive layer to the semiconductor substrate surface of the surface type optical semiconductor device by a technique such as etching.
[0015]
  <Adhesion of other processed substrates to planar optical semiconductor devices>
  The second5The surface-type optical semiconductor module with fiber of the invention is the first module.MysteriousIn a surface type optical semiconductor module with fiber,
  A protrusion or groove for alignment formed on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device,
  The semiconductor substrate surface of the surface type optical semiconductor device, a semiconductor or glass or other substrate in which a protrusion or groove for alignment is previously formed by a technique such as etching, the light emitting portion of the surface type optical semiconductor device, The light emitting part, the light receiving part or the light input / output part and the protrusion or groove are arranged so that the light receiving part or the light input / output part is at the center of the protrusion or groove formed in advance on the other semiconductor or glass substrate. It is formed by aligning and bonding.
[0017]
  <Metal ferrule: 1 electrode on the surface, 1 electrode on the opposite surface>
  The second6The surface type optical semiconductor module with a fiber of the invention is the first invention to the first invention.5In the surface type optical semiconductor module with a fiber of the invention,
  The ferrule is formed of a metal such as nickel, kovar, copper, stainless steel, and when the surface-type optical semiconductor device is mounted on the ferrule, the surface-type optical semiconductor device is formed with solder formed on one end surface of the ferrule. By electrically connecting, the first electrode of the planar optical semiconductor device is drawn out to the outside,
  Further, a groove is provided on a side surface of the ferrule, and an electrode wire that is electrically insulated from the ferrule is disposed in the groove, and an alignment surface of the electrode wire and the ferrule in the planar optical semiconductor device is By connecting the second electrode formed on the opposite surface with a bonding wire,
  The planar optical semiconductor device is configured to be energized from the outside through the ferrule and the electrode wire.
[0018]
  <Metal ferrule: Surface 2-electrode type>
  The second7The surface type optical semiconductor module with a fiber of the invention is the first invention to the first invention.5In the surface type optical semiconductor module with a fiber of the invention,
  The ferrule is formed of a metal such as nickel, kovar, copper, stainless steel, and when the surface optical semiconductor device is mounted on the ferrule, the surface optical semiconductor device is formed with solder formed on one end surface of the ferrule. Electrically connect,
  Further, a groove is provided on a side surface of the ferrule, and an electrode wire that is electrically insulated from the ferrule is disposed in the groove, and the electrode wire is formed on an alignment surface of the ferrule in the planar optical semiconductor device. And connected to the second electrode,
  When the alignment surface of the planar optical semiconductor device is the epitaxial layer side surface, the first electrode and the second electrode formed on the epitaxial layer side surface are respectively connected to the ferrule and the electrode. Pull out directly through the wire and
  Alternatively, when the alignment surface of the planar optical semiconductor device is the back surface on the semiconductor substrate side, the first electrode and the second electrode formed on the epitaxial layer side surface are opened in the semiconductor substrate, respectively. By pulling out to the back side of the semiconductor substrate side through the through-hole type electrode formed by embedding a conductive material in the through-hole, and pulling out to the outside through the ferrule and the electrode wire,
  The planar optical semiconductor device is configured to be energized from the outside through the ferrule and the electrode wire.
[0019]
<Sleeve module 1: Insert ferrule with device and optical fiber only ferrule>
  The second8The surface type optical semiconductor module with a fiber of the invention is the first invention to the first invention.7The optical fiber module with a fiber according to any one of the inventions is provided as a first block, the first block is inserted into the sleeve from one side of the sleeve, and another optical fiber is inserted into another ferrule. The second ferrule with a fiber is provided as a second block, and the second block is inserted into the sleeve from the opposite side of the sleeve,
  By arranging the center of the light emitting unit, the light receiving unit or the light input / output unit of the planar optical semiconductor device included in the second block to coincide with the center of the optical fiber included in the second block,
  The surface optical semiconductor device and the optical fiber can be optically coupled.
[0020]
  <Sleeve module 1: lens insertion>
  The second9The surface type optical semiconductor module with fiber of the invention is8In the surface type optical semiconductor module with a fiber of the invention,
  The sleeve is positioned between the first block and the second block.Gradient index lensThe first block and the first block are optically coupled by using the optical element.
[0021]
  <Limitation of sleeve module 1: planar optical semiconductor laser module>
  The second10The surface type optical semiconductor module with fiber of the invention is8Invention or No.9In the surface type optical semiconductor module with a fiber of the invention,
  The surface-type optical semiconductor device is a surface-emitting semiconductor laser;
  The main output light from the surface-emitting semiconductor laser is extracted from either one of the optical fibers included in the first block or the second block, and the optical fiber included in the first block or the second block. From any one of the above, the monitor light from the surface emitting semiconductor laser is extracted.
[0022]
  <Limitation of Sleeve Module 1: Optically Pumped Surface Type Optical Semiconductor Laser Module>
  The second11The surface type optical semiconductor module with fiber of the invention is8Invention or No.9In the surface type optical semiconductor module with a fiber of the invention,
  The surface-type optical semiconductor device is a surface-emitting semiconductor laser;
  By introducing the pumping light for the surface emitting semiconductor laser through the optical fiber included in the first block or the second block, the surface emitting semiconductor laser is irradiated,
  The main output light from the surface emitting semiconductor laser, or the main output light and the monitor light are configured to be extracted from an optical fiber included in the first block or the second block.
[0023]
  <Limitation of sleeve module 1: wavelength-tunable surface type optical semiconductor laser module>
  The second12The surface type optical semiconductor module with fiber of the invention is8No. from invention11In the surface type optical semiconductor module with a fiber of the invention,
  The surface-type optical semiconductor device is a surface-emitting semiconductor laser;
  In this surface emitting semiconductor laser, all or part of the upper Bragg reflecting mirror is not formed, and a dielectric multilayer mirror is formed on the end face of the optical fiber of the second block,
  Between the lower semiconductor mirror formed on the surface emitting semiconductor laser and the external dielectric multilayer mirror, the surface emitting semiconductor laser is oscillated by current injection or optical excitation,
  Furthermore, a piezo element is bonded to the ferrule of the first block or the second block, and the lower block is formed by mechanically moving the first block or the second block in the axial direction of the sleeve with the piezo element. The oscillation wavelength of the surface emitting semiconductor laser is variable by changing the distance between the semiconductor mirror and the dielectric multilayer mirror.
[0024]
  <Sleeve module 2: Insert two sets of ferrules with device>
  The second13The surface type optical semiconductor module with a fiber of the invention is the first invention to the first invention.7Each of the surface optical semiconductor modules with fibers according to the invention is provided as a first block and a second block,
  By inserting the first block into the sleeve from one side of the sleeve, and inserting the second block into the sleeve from the opposite side of the sleeve,
  The center of the light emitting unit, the light receiving unit, or the light input / output unit of the planar optical semiconductor device included in the first block is the light emitting unit, the light receiving unit, or the light input of the planar optical semiconductor device included in the second block. Arrange it so that it matches the center of the output section.
  The surface optical semiconductor device and the optical fiber can be optically coupled.
[0025]
  <Sleeve module 2: lens insertion>
  The second14The surface type optical semiconductor module with fiber of the invention is13In the surface type optical semiconductor module with a fiber of the invention,
  A cell in the sleeve so as to be located between the first block and the second block;Gradient index lensThe first block and the first block are optically coupled by using the optical element.
[0026]
  <Limitation of sleeve module 2: surface emitting semiconductor laser module with photodiode>
  The second15The surface type optical semiconductor module with fiber of the invention is13Invention or No.14In the surface type optical semiconductor module with a fiber of the invention,
  The surface optical semiconductor device of the first block is a surface emitting semiconductor laser, and the surface optical semiconductor device of the second block is a detector such as a photodiode;
  The main output light of the surface-emitting semiconductor laser is extracted from the optical fiber of the first block, and the monitor electrical output of the detector is extracted from the second block.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the ferrule and sleeve, which are the most accurate optical fiber components related to optical fiber communication and the lowest price, are used as module components for surface optical semiconductor devices such as surface emitting semiconductor lasers. Then, by processing these components using general-purpose technology, a surface optical semiconductor module with a fiber such as a surface emitting semiconductor laser module with a fiber is provided that is very inexpensive.
[0030]
In particular, it is important to use a metal ferrule with excellent heat dissipation and high processing accuracy. In recent years, metal ferrules with high dimensional accuracy have become commercially available. There are various methods for producing metal ferrules, but those using electroforming technology (electro homing) are very accurate. Furthermore, the present invention provides a surface emitting semiconductor laser module with a fiber capable of changing the wavelength by mechanically moving a ferrule within a sleeve.
[0031]
Commercially available metal ferrules are often made of nickel (Ni), with a high-precision inner diameter of 125 μm + 1 μm (error) and an outer diameter of 0.5 mmφ, 1 mmφ, 2.5 mmφ ± 1 μm (error) Can be obtained at low cost. In addition, high-precision ceramics, glass, and plastic sleeves for inserting ferrules have become available at low cost.
[0032]
  MoneyThe tip of a ferrule made of a genus is turned into a convex shape with a diameter of 100 m2 m (error) by machining a cylindrical protrusion on one end surface of the ferrule, or a ring-shaped groove is formed on one end surface of the ferrule FormingIt was.The height of the protrusion or the depth of the groove is preferably about several tens to 100 m. Etching may be used to process the protrusions in addition to the lathe process. Alternatively, in order to form a protrusion on the tip (one end face) of the ferrule, two types of ferrules having different diameters are produced, and an optical fiber having a diameter of 125 m is inserted into these ferrules so that the central axes of the two ferrules are aligned. Two ferrules may be bonded together (claims)1). Solder is deposited on one end face of the ferrule in which the protrusions or grooves are thus formed.
[0033]
  Next, the diameter of the protrusion or groove (several hundred meters) is used to fit the protrusion or groove on one end face of the ferrule around the light emitting portion of a surface optical semiconductor device such as a surface emitting semiconductor laser. A ring-shaped or pin-shaped protrusion is formed by direct etching on a circumference having a corresponding diameter.2). However, since the etching rate of the semiconductor is slow, an organic thick film such as polyimide is applied to the back surface of the substrate, and this film may be etched to form protrusions.3). Alternatively, after bonding another semiconductor substrate to the semiconductor substrate of the planar optical semiconductor device, the other semiconductor substrate thus bonded may be processed by a technique such as etching to form protrusions (claims).4), Another semiconductor substrate on which protrusions are formed in advance may be bonded to the semiconductor substrate surface of the planar optical semiconductor device (claim).5).
[0034]
  The above is an example in which a ring-shaped or pin-shaped protrusion on the surface type optical semiconductor device side is fitted into a protrusion or groove formed on the ferrule side, but a ring-shaped or pin-shaped protrusion formed on the ferrule side. May be fitted into a protrusion or groove formed on the surface type optical semiconductor device side, or the entire surface type optical semiconductor device may be fitted into the groove formed on the ferrule side.Yes.Further, the surface (alignment surface) of the planar optical semiconductor device fitted into the ferrule may be the back surface of the semiconductor substrate or the surface of the semiconductor substrate on which the device is processed, that is, the epitaxial layer side surface.
[0035]
  The surface emitting semiconductor laser is mounted on the tip (one end face side) of the metal ferrule by the method as described above. Thereby, the light emitting part of the surface emitting semiconductor laser can be mounted with an accuracy of 2 m at the center of the ferrule. Further, the energization of the mounted surface emitting semiconductor laser can be performed through the metal ferrule itself and a covered conductor (electrode wire) inserted into a groove provided on the side surface of the metal ferrule. That is, when the semiconductor substrate side rear surface of the surface emitting semiconductor laser is mounted facing the metal ferrule, the electrode formed on the semiconductor substrate side rear surface of the surface emitting semiconductor laser and the metal ferrule are directly electrically connected, The electrode on the epitaxial surface side surface of the surface emitting semiconductor laser and the coated conductor (electrode wire) are electrically connected by a bonding wire.6).
[0036]
  When the surface of the surface emitting semiconductor laser is mounted so that the surface on the epitaxial surface side faces the metal ferrule, the first electrode on the surface of the epitaxial layer of the surface emitting semiconductor laser and the metal ferrule are directly electrically connected, The second electrode on the epitaxial surface side surface of the surface emitting semiconductor laser is also directly electrically connected to the coated conductor.7). Alternatively, even when the semiconductor substrate side rear surface of the surface emitting semiconductor laser and the metal ferrule are mounted facing each other, the first and second electrodes on the epitaxial surface side surface of the surface emitting semiconductor laser are formed as through-hole electrodes, that is, If the first and first electrodes are pulled out to the back side of the semiconductor substrate by a technique such as making a through hole in the semiconductor substrate, insulating the side surface of the through hole, and further embedding a conductive material in the through hole, a bonding wire Can be directly connected to the electrode wire (coated conductor) and the metal ferrule without using the7).
[0037]
  Further, a surface emitting semiconductor laser module with a fiber in which a surface emitting semiconductor laser and a ferrule with a fiber as described above are integrated is set as a first block, and the first block is inserted from one side of the sleeve and the opposite side is inserted. When the second ferrule with a fiber (second block formed by inserting another optical fiber into another ferrule) is inserted from the opposite side of the sleeve, the center of the optical fiber core and the light emitting part of the surface emitting semiconductor laser Are perfectly parallel and the positions coincide with an accuracy of 2 m (error).8, 10). In this case, light may be coupled by bringing the optical fiber close to the surface emitting semiconductor laser, or a SELFOC lens having a diameter corresponding to the diameter of the ferrule.(Registered trademark: General name is a gradient index lens)May be inserted into the sleeve so as to be positioned between the first block and the second block for lens coupling.9).
[0038]
  In addition, one of the first block and the second block is used for taking out main output light from the surface emitting semiconductor laser, and the other optical fiber is used for taking out monitor light from the surface emitting semiconductor laser. May be. In the case where the surface emitting semiconductor laser is a photo-pumped surface emitting semiconductor laser, the optical fiber of either the first block or the second block is supplied with pumping light (pumping light) and monitor light. The other optical fiber may be used for taking out the main output light.11). Further, the surface emitting semiconductor laser does not form all or part of the upper Bragg reflecting mirror, but forms the active layer and the lower semiconductor mirror, and the end face of the optical fiber inserted into the ferrule of the second block has multiple layers. The dielectric film is coated to form a dielectric multilayer mirror, and the ferrule of the first block or the second block is adhered to the piezo element, and the first block (ferrule or the like) or the second block is adhered to the piezo element. The distance between the surface emitting semiconductor laser (lower semiconductor mirror) and the end face of the optical fiber on which the dielectric multilayer mirror is formed can be changed by mechanically moving one block (such as a ferrule) within the sleeve. Then, the oscillation wavelength of the surface emitting semiconductor laser can be changed.12).
[0039]
  The above is an example in which a surface-type optical semiconductor device such as a surface-emitting semiconductor laser is mounted only on the first block inserted into the sleeve, but a detector such as a photodiode is also provided on the ferrule of the second block. If mounted, the optical output of the surface emitting semiconductor laser can be monitored directly.13, 15). Even in this case, a pair of surface optical semiconductor devices such as a surface emitting semiconductor laser and a photodiode may be directly optically coupled, or SELFOC having a diameter corresponding to the diameter of the ferrule. The lens may be inserted into the sleeve so as to be positioned between the first block and the second block for lens coupling.14).
[0040]
  Further, a surface emitting semiconductor laser module (block) with a fiber in which a surface emitting semiconductor laser as described above and a ferrule with a fiber are integrated is used as a high frequency mount.AndHigh frequency connector capToIf it is inserted into a pre-formed hole and electrically connected to a high-frequency mount or a high-frequency connector by a connecting means such as a bonding wire, a surface emitting semiconductor laser module with a fiber (high-frequency mount module or high-frequency connector module) can be easily obtained. Can be produced.
[0041]
As described above, the point of the present invention is that the front end (one end surface) of the ferrule and the back surface of the surface emitting semiconductor laser on the semiconductor substrate side so that the center of the metal ferrule and the center of the light emitting portion of the surface emitting semiconductor laser coincide with each other by passive alignment. Alternatively, by accurately processing the surface on the epitaxial layer side to form protrusions or grooves, both are fitted, and there are various shapes other than those described above, but all of them are included.
[0042]
(First embodiment)
FIGS. 1 to 13 show a first embodiment of a fiber-optic surface type optical semiconductor module of the present invention. FIGS. 1 to 3 show the process of processing the tip (one end face) of the metal ferrule, and FIGS. 4 to 7 show the process of forming alignment protrusions on the back surface of the surface emitting semiconductor laser. 8 to 11 show a process of mounting the surface emitting semiconductor laser on the tip (one end face) of the metal ferrule. 12 and 13 are enlarged views of a connection portion between the surface emitting semiconductor laser, the metal ferrule, and the optical fiber, and the case where the semiconductor substrate side rear surface of the surface emitting semiconductor laser and the metal ferrule are opposed to each other (FIG. 12). This shows the case where the epitaxial layer side surface of the surface emitting semiconductor laser and the metal ferrule are connected to face each other (FIG. 13).
[0043]
In these drawings, 10 is a surface emitting semiconductor laser, and 11 is a light emitting portion of the surface emitting semiconductor laser 10. The light emitting unit 11 includes a mesa portion upper Bragg reflection mirror (DBR) 11a, an active layer (surface emitting light emitting portion) 11b, and a lower semiconductor mirror 11c.
[0044]
In the figure, 12 is a semiconductor substrate of the surface emitting semiconductor laser 10, 13 is a metal ferrule, 14 is an alignment projection formed by grinding one end surface of the metal ferrule 13, and 15 is a metal ferrule 13. 1 is formed on the side surface of the metal ferrule 13 by grinding one end face (in the case of FIG. 2) or the surface of the semiconductor substrate of the surface emitting semiconductor laser 10 (in the case of FIG. 13) into a ring shape. The groove for taking out the electrode, 17 is solder formed on one end surface of the metal ferrule 13, and 18 is a ring or pin on the circumference centering the light emitting portion 11 on the back surface side of the semiconductor substrate 12 of the surface emitting semiconductor laser 10. Alignment protrusions formed in the shape (in the case of FIGS. 4 to 7), or alignment protrusions formed in a ring shape on one end face of the metal ferrule 13 (in the case of FIG. 13), 1 Is an electrode surface formed on the back surface of the semiconductor substrate 12 of the surface emitting semiconductor laser 10 (no electrode is formed in a portion through which light passes), and 20 is formed on the surface of the semiconductor substrate 12 of the surface emitting semiconductor laser 10. It is a pad electrode.
[0045]
In the same figure, 21 is a bonding wire coming out of the pad electrode 20, 22 is an electrode wire (covered conductor) inserted into the groove 16 on the side surface of the metal ferrule 13 and electrically insulated from the metal ferrule 13. Reference numeral 23 denotes a metal ferrule whose diameter is accurately adjusted, which is cut into a short length (small piece of metal ferrule), 24 an optical fiber, 24 a a core of the optical fiber 24, and 25 a semiconductor substrate 12 of the surface emitting semiconductor laser 10. A film (insulating layer) made of polyimide or the like formed on the back surface of the semiconductor substrate, 26 is a semiconductor substrate on which the protrusions 18 are formed in advance, 28 is a substrate electrode formed on the surface of the semiconductor substrate 12 of the surface emitting semiconductor laser 10, and 29 is a light passage 30A is a laser beam (laser beam) emitted from the back surface of the surface emitting semiconductor laser 10, and 30B is a laser beam emitted from the surface of the surface emitting semiconductor laser 10. A laser beam).
[0046]
The surface emitting semiconductor laser includes a 650 nm band, a 780 nm band, an 850 nm band, a 980 nm band, a 1300 nm band, and a 1550 nm band surface emitting semiconductor laser formed on a GaAs or AlGaAs substrate, or a 1300 nm band formed on an InP substrate. The present invention is applicable to any type of surface emitting semiconductor laser. Here, the surface emitting semiconductor laser 10 will be described by taking a surface emitting semiconductor laser formed on a GaAs substrate as an example. The surface optical semiconductor device to which the present invention is applied is not limited to a surface emitting semiconductor laser, but includes a photodiode, a surface optical amplifier, a surface optical gate, and the like. Although a mesa type surface emitting semiconductor laser is shown here, the present invention is not limited to this.
[0047]
First, processing of the metal ferrule 13 will be described with reference to FIGS.
[0048]
A metal ferrule 13 made of Ni and having an outer diameter of 1.25 mmφ as shown in FIGS. 1 (a) and 2 (a) has an outer diameter of 300 μmφ ± 2 μm centered on the central axis of the metal ferrule 13 with a lathe at one end face. Whether or not a cylindrical protrusion 14 positioned on the circumference centered on the central axis of the metal ferrule 13 as shown in FIG. Alternatively, by cutting into a concave shape, a ring-shaped groove 15 located on the circumference around the central axis of the metal ferrule 13 as shown in FIG.
[0049]
Alternatively, as shown in FIG. 3 (a), a metal ferrule 13 having an outer diameter of 1.25 mmφ and a metal ferrule 23 having an outer diameter of 300 μmφ ± 2 μm (error) are cut to a length of about 0.5 mm (the metal ferrule 3 (b), and an optical fiber 24 having a diameter of 125 μmφ is inserted into the hole of the metal ferrule 13 and the hole of the metal ferrule (small piece) 23 as shown in FIG. By inserting a wire rod having the same diameter of 125 μmφ, the central axes of both metal ferrules 13 and 23 are made to coincide, and in this state, both metal ferrules 13 and 23 are bonded together with an adhesive. Thus, a projection 14 made of a small piece of the metal ferrule 23 is formed on one end face of the metal ferrule 13. The metal ferrules 13 and 23 may be made of Kovar, copper, stainless steel, etc. in addition to nickel (Ni).
[0050]
After forming the protrusions or grooves, as shown in FIGS. 1C, 2C, 3C, and 3D, the side surface of the metal ferrule 13 has a width of about 200 μm and a depth of 200 μm. The groove 16 is formed along the axial direction of the metal ferrule 13. Subsequently, as shown in FIGS. 1D, 2D, 3E, and 3F, the electrode wire 22 is inserted into the groove 16 and fixed to the metal ferrule 13 with an adhesive. . The electrode wire 22 is covered with an insulating material and is electrically insulated from the metal ferrule 13. Soldering is performed by vapor deposition on one end surface of the metal ferrule 13 (the front end surface of the protrusion 14 in FIGS. 1D, 3E, and 3F, and the inner portion of the groove 15 in FIG. 2D). 17 is formed.
[0051]
3 (c) and 3 (e) show a case where the wire rod inserted for alignment of the metal ferrules 13 and 23 is pulled out. In this case, the optical fiber 24 is later connected to the metal ferrule 13. , 23. FIGS. 3D and 3F show a case where the optical fiber 24 inserted for alignment of the metal ferrules 13 and 23 is inserted into the metal ferrules 13 and 23 as they are and used for a module. .
[0052]
Next, processing of the surface emitting semiconductor laser 10 will be described with reference to FIGS.
[0053]
On the back surface (lower surface in the figure) of the GaAs substrate 12 of the surface emitting semiconductor laser 10 shown in FIG. 4A, the light emitting portion 11 of the surface emitting semiconductor laser 10 is provided as shown in FIGS. A ring-shaped (cylindrical) protrusion 18 located on the circumference having a diameter of 300 μmφ + 2 μm (error) at the center is formed by etching. Alternatively, on the back surface of the GaAs substrate 12 of the surface emitting semiconductor laser 10 shown in FIG. 5A, the light emitting portion 11 of the surface emitting semiconductor laser 10 is centered as shown in FIGS. 5B and 5C. A plurality of pin-like protrusions 18 positioned on a circumference of 300 μmφ + 2 μm in diameter (error) (a circle virtually shown by a one-dot chain line in FIG. 5C) is formed by etching.
[0054]
More specifically, the GaAs substrate 12 of the surface emitting semiconductor laser 10 is polished to a thickness of about 100 to 200 μm, and this GaAs substrate 12 is bonded to a supporting (reinforcing) glass substrate not shown in the drawing with wax. After that, the projection 18 is formed by photo processing, etching, etc., and electrode attachment is performed. At this time, it is necessary to align the etching mask by simultaneously viewing the front surface and the back surface of the GaAs substrate 12, but by using a mask aligner that transmits infrared light, the alignment of the back surface and the front surface of the GaAs substrate 12 is 1 μm. It can be realized with the following accuracy. Etching may be either dry etching or wet etching. In addition, the glass substrate for support is removed after completion | finish of a process.
[0055]
On the other hand, since the etching rate of the semiconductor substrate is slow, when deep etching is performed, polyimide or the like is applied to the back surface of the GaAs substrate 12 to form a thick film (insulating layer) 25 as shown in FIG. The film (insulating layer) 25 is etched as shown in FIGS. 6B and 6C to form a plurality of pin-like protrusions 18 positioned on the circumference centering on the light emitting portion 11. May be. The height of the protrusion 18 may be several μm to several tens of μm. Also in this case, the protrusion 18 may be ring-shaped.
[0056]
Further, as shown in FIG. 7A, a semiconductor substrate 26 on which a plurality of pin-shaped protrusions 18 are formed in advance is prepared, and the surface of the semiconductor substrate 26 and the surface thereof are prepared as shown in FIGS. The protrusions 18 may be formed on the back surface side of the GaAs substrate 12 by bonding the GaAs substrate 12 of the light emitting semiconductor laser 10 with the wafer bonding technique. The semiconductor substrates 12 and 26 may be bonded together via polyimide (adhesive layer). Also in this case, the protrusion 18 may be ring-shaped.
[0057]
Although not shown, by bonding another semiconductor or a glass substrate directly or via an adhesive layer to the GaAs substrate 12 of the surface emitting semiconductor laser 10, the semiconductor substrate is processed by a technique such as etching. The protrusion 18 may be formed.
[0058]
After the protrusions are formed, an Au electrode 19 is formed on the back surface of the GaAs substrate 12 of the surface emitting semiconductor laser 10 as shown in FIGS. 4D, 5D, and 6D, or FIG. The Au electrode 19 is formed on the back surface of the semiconductor substrate 26 as shown in FIG. At this time, a portion 29 through which light on the back surfaces of the semiconductor substrates 12 and 26 passes is opened without forming the Au electrode 19.
[0059]
8 to 11 show a process of mounting the surface emitting semiconductor laser 10 on the tip (one end face) of the metal ferrule 13.
[0060]
FIG. 8 shows a case where a surface emitting semiconductor laser 10 (see FIG. 4) in which a ring-shaped protrusion 18 is formed is mounted on the tip of a metal ferrule 13 (see FIG. 1) in which a cylindrical protrusion 14 is formed. As shown in FIG. 8A, the surface of the surface emitting semiconductor laser 10 on which the protrusions 18 are formed is opposed to the surface of the metal ferrule 13 on which the protrusions 14 are formed, and FIGS. c) As shown in (cross-sectional view), the projections 14, 14 are formed by fitting the inner circumferential surface of the ring-shaped projection 18 of the surface emitting semiconductor laser 10 into the outer circumferential surface of the columnar projection 14 of the metal ferrule 13. 18 are fitted together.
[0061]
FIG. 9 shows a case where a surface emitting semiconductor laser 10 (see FIG. 4) in which a ring-shaped protrusion 18 is formed is mounted on the tip of a metal ferrule 13 (see FIG. 2) in which a ring-shaped groove 15 is formed. As shown in FIG. 9A, the surface of the surface emitting semiconductor laser 10 on which the protrusion 18 is formed is opposed to the surface of the metal ferrule 13 on which the groove 15 is formed, so that FIGS. c) As shown in the sectional view, the ring-shaped protrusions 18 of the surface emitting semiconductor laser 10 are fitted into the ring-shaped grooves 15 of the metal ferrule 13, and the grooves 15 and the protrusions 18 are fitted to each other. Match.
[0062]
10 shows a case where a surface emitting semiconductor laser 10 (see FIGS. 5, 6, and 7) having a pin-like protrusion 18 formed on the tip of a metal ferrule 13 (see FIG. 1) having a cylindrical protrusion 14 is mounted. In this case, as shown in FIG. 10A, the surface of the surface emitting semiconductor laser 10 on which the protrusions 18 are formed is opposed to the surface on which the protrusions 14 of the metal ferrule 13 are formed. b) and FIG. 10C (cross-sectional view), the plurality of pin-shaped protrusions 18 of the surface emitting semiconductor laser 10 are fitted into the outer peripheral surface of the columnar protrusion 14 of the metal ferrule 13, and these The protrusions 14 and 18 are fitted to each other.
[0063]
FIG. 11 shows a case where a surface emitting semiconductor laser 10 (see FIGS. 5, 6, and 7) in which a pin-like protrusion 18 is formed at the tip of a metal ferrule 13 (see FIG. 2) in which a ring-shaped groove 15 is formed is mounted. In this case, as shown in FIG. 11A, the surface of the surface emitting semiconductor laser 10 on which the protrusions 18 are formed is opposed to the surface of the metal ferrule 13 on which the protrusions 14 are formed. As shown in FIG. 11B and FIG. 11C (cross-sectional view), a plurality of pin-shaped protrusions 18 of the surface emitting semiconductor laser 10 are fitted into the ring-shaped grooves 15 of the metal ferrule 13, and these grooves 15 are inserted. And the protrusion are fitted to each other.
[0064]
Subsequently, as shown in FIGS. 8C, 9C, 10C, and 11C, the protrusion 14 or the groove 15 of the metal ferrule 13 and the protrusion 18 of the surface emitting semiconductor laser 10 are formed. By heating in the fitted state, the solder 17 coated in advance on one end face of the metal ferrule 13 is melted, and the surface emitting semiconductor laser 10 (electrode 19) and the metal ferrule 13 are electrically and mechanically connected by this solder 17. Connect. Thus, the surface emitting semiconductor laser 10 is mounted on one end face of the metal ferrule 13 so as to cover it. At this time, the center of the metal ferrule 13 and the center of the light emitting portion 11 of the surface emitting semiconductor laser 10 coincide with each other with an error of ± 2 μm or less.
[0065]
Thereafter, as shown in FIGS. 8D, 9D, 10D, and 11D, pads formed on the surface of the GaAs substrate 12 of the surface emitting semiconductor laser 10 by the bonding wires 21 are used. The electrode 20 and the electrode wire 22 inserted into the groove 16 on the side surface of the metal ferrule 13 are electrically connected. For this reason, the electrode 19 on the back surface side (semiconductor substrate side back surface) of the surface emitting semiconductor laser 10 is drawn to the outside through the metal ferrule 13, and the pad electrode 20 on the surface side (epitaxial layer side surface) of the surface emitting semiconductor laser 10. Is extracted to the outside through the electrode wire 22.
[0066]
FIG. 12 is an enlarged view of a connecting portion when the semiconductor substrate side rear surface of the surface emitting semiconductor laser 10 is connected to one end surface of the metal ferrule 13 (see FIG. 8), and FIG. A front view of the ferrule 13 viewed from the axial direction, and FIG. As shown also in FIG. 12, the electrode 19 on the semiconductor substrate side rear surface of the surface emitting semiconductor laser 10 and one end surface of the metal ferrule 13 are electrically connected by solder 17, and the surface of the semiconductor substrate of the surface emitting semiconductor laser 10. The pad electrode 20 on the side (epitaxial layer side surface) and the electrode wire 22 that is inserted in the groove 16 on the side surface of the metal ferrule 13 while being insulated from the metal ferrule 13 are electrically connected via a bonding wire 21. Yes.
[0067]
In the above description, the protrusion 18 is formed on the surface emitting semiconductor laser 10 and the protrusion 14 or the groove 15 is formed on the metal ferrule 13. However, the present invention is not limited to this. A groove may be formed as appropriate, and a protrusion or groove may also be formed in the metal ferrule 13 so that both protrusions or grooves fit into each other.
[0068]
In the above description, the case where the semiconductor substrate side rear surface of the surface emitting semiconductor laser 10 and the one end surface of the metal ferrule 13 are connected to face each other has been described. The surface side (epitaxial layer side surface) and one end face of the metal ferrule 13 may be opposed to each other. In this case, alignment protrusions or grooves are formed on the surface side (epitaxial layer side) of the GaAs substrate 12 of the surface emitting semiconductor laser 10. Usually, since the surface side of a semiconductor substrate such as the GaAs substrate 12 is processed, mask alignment is easy. In the case of forming a high protrusion on the surface of the semiconductor substrate, a protrusion may be formed by applying a thick film such as polyimide on the surface of the semiconductor substrate and etching the thick film. In addition, when grooves are formed on the surface of the semiconductor substrate, the surface of the semiconductor substrate may be directly etched deeply.
[0069]
FIG. 13 is an enlarged view of a connection portion showing an example in which the surface side (epitaxial layer side) of the surface emitting semiconductor laser 10 and one end face of the metal ferrule 13 are connected to face each other. FIG. A front view of the metal ferrule 13 seen from the axial direction, and FIG. 13B shows a cross-sectional view.
[0070]
In FIG. 13, a ring-shaped groove 15 is formed on the surface of the GaAs substrate 12 (surface on the epitaxial layer side) of the surface-emitting semiconductor laser 10 on the circumference around the light-emitting portion 11, and one end surface of the metal ferrule 13. A ring-shaped protrusion 18 is formed on the circumference around the central axis of the metal ferrule 13. Then, the surface of the surface emitting semiconductor laser 10 on which the groove 15 is formed is opposed to the surface on which the protrusion 18 of the metal ferrule 13 is formed, and the ring of the metal ferrule 13 is placed in the ring-shaped groove 14 of the surface emitting semiconductor laser 10. The projections 18 and the grooves 15 are fitted so that the projections 18 are fitted.
[0071]
In FIG. 13, a substrate electrode 28 is formed on the surface of the GaAs substrate 12 of the surface emitting semiconductor laser 10. The substrate electrode 28 and the metal ferrule 13 are electrically connected by solder 17 formed on one end surface of the metal ferrule 13. Mechanically and mechanically connected. Further, the pad electrode 20 formed on the surface of the GaAs substrate 12 of the surface emitting semiconductor laser 10 is also electrically connected directly to the electrode wire 22 inserted in the groove 16 on the side surface of the metal ferrule 13 so as to be insulated from the metal ferrule 13. It is connected. Accordingly, the substrate electrode 28 of the surface emitting semiconductor laser 10 is drawn out through the metal ferrule 13, and the pad electrode 20 of the surface emitting semiconductor laser 10 is drawn out through the electrode line 22. In FIG. 13, in order to align the position of the electrode line 22 with the position of the pad electrode 20, the depth of the groove 16 is made relatively deep, and the electrode line 16 is inserted deeply into the groove 16. Further, as the groove 16 is deepened in this way, the ring-shaped protrusion 18 is notched in the groove 16 portion.
[0072]
Also, here, the electrode is taken out from the front and back surfaces of the semiconductor substrate. However, a through-hole is formed in the semiconductor substrate from the front surface to the back surface, and a conductive material is embedded in the through-hole to penetrate the semiconductor substrate. A through-hole electrode may be formed, and the electrode may be drawn from one surface of the semiconductor substrate to the other surface via the through-hole electrode.
[0073]
Next, FIG. 14 shows a structure in which this metal ferrule mounted with a surface emitting semiconductor laser is placed in an insulating sleeve to form a module with a fiber. 14A is a perspective view, and FIG. 14B is a cross-sectional view. In FIG. 14, 31 is a non-metallic (insulating) sleeve, 32 is a ferrule, 33 is an optical fiber, and the other symbols are as described above.
[0074]
In FIG. 14, the optical fiber 24 is inserted into the metal ferrule 13 (see FIGS. 8 to 11) mounted with the surface emitting semiconductor laser produced as described above to obtain a surface emitting semiconductor laser module with a fiber. In this case, the optical fiber 24 becomes a monitoring optical fiber for taking out the monitoring light emitted from the back surface of the surface emitting semiconductor laser 10. However, in the case of a surface emitting semiconductor laser extracted from the back surface, the light extracted on the back surface side becomes main signal light (main output light), and the light extracted on the opposite side (front surface side) becomes monitor light. 24 is used to extract main output light.
[0075]
Then, the surface emitting semiconductor laser module with a fiber is provided as a first block, and the first block is inserted into the sleeve 31 from the right side of the sleeve 31 as indicated by an arrow A. Next, a ferrule with a fiber formed by inserting the optical fiber 33 into the ferrule 32 is provided as a second block, and the second block is connected to the sleeve 31 from the left side of the sleeve 31 as indicated by an arrow B. Insert until the last minute. After the sleeve is inserted, the first block and the second block are fixed to the sleeve 31 with an adhesive or the like.
[0076]
By inserting the first block and the second block into the sleeve 31 as described above, the center of the light emitting unit 11 of the surface emitting semiconductor laser 10 included in the first block is the light included in the first block. The main output light or monitor light emitted from the surface emitting semiconductor laser 10 is taken out by the optical fiber 33 so as to coincide with the center of the fiber 33. At this time, the center of the light emitting portion 11 of the surface emitting semiconductor laser 10 and the center of the optical fiber 33 are matched with an accuracy of error of ± 2 μm, so that a coupling loss of 3 dB can be realized at worst by passive alignment. Moreover, since it is passive alignment using the sleeve 31, an inexpensive module can be realized.
[0077]
Here, although the optical fiber 33 and the surface emitting semiconductor laser 10 are butt joints, a selfoc lens is inserted between the optical fiber 33 and the surface emitting semiconductor laser 10, and the surface emitting semiconductor laser 10 is formed by this selfoc lens. The light from the light beam may be collected and put into the optical fiber 33. A lens having a diameter corresponding to the inner diameter of the sleeve 31 (the outer diameter of the ferrules 13 and 32) is commercially available.
[0078]
The two optical fibers 24 and 33 can be used for taking out the main output light and the monitor light from the surface emitting semiconductor laser 10 as described above, and the surface emitting semiconductor laser 10 is a light-excited surface emitting type. In the case of a semiconductor laser, one of the optical fibers 24 and 33 (for example, the optical fiber 24) is used for pumping light input and monitor light extraction, and the other of the optical fibers 24 and 33 (for example, the optical fiber 33) is mainly used. It can also be used for extracting output light.
[0079]
Further, as the second block facing each other, instead of inserting the optical fiber 24 into the metal ferrule 13 in the first block, a surface optical semiconductor device in which a detector such as a photodiode is directly mounted is manufactured. If the second block is inserted into the sleeve 31 so as to face the first block, the monitor electrical output of the detector can be taken out through the metal ferrule 13 and the electrode wire 22, and surface emission is performed by the detector. The light of the semiconductor laser 10 can be directly monitored.
[0080]
(Second embodiment)
FIG. 15 shows a structure in which a surface emitting semiconductor laser is mounted on a high-speed mount (high-frequency mount) as a second embodiment of the present invention. FIG. 15 (a) is an overall perspective view, and FIG. It is an expanded sectional view of a surface emitting semiconductor laser mounting part.
[0081]
In FIG. 15, the surface emitting semiconductor laser module with a fiber described in the first embodiment, that is, a protrusion or groove formed on one end surface of the metal ferrule 13, and the surface on the epitaxial layer side or the semiconductor substrate side rear surface of the surface emitting semiconductor laser 10. The surface-emitting semiconductor laser is formed by fitting the protrusions or grooves formed on each other and passively aligning the center of the light-emitting portion 11 of the surface-emitting semiconductor laser 10 and the center of the optical fiber 24 inserted into the metal ferrule 13. A surface-emitting semiconductor laser module with a fiber that enables optical coupling between 10 light emitting units 11 and an optical fiber 24 is applied to a high-speed mount.
[0082]
In FIG. 15, reference numeral 41 denotes a normal high-speed mount for a semiconductor laser (a high-frequency mount that is a general-purpose semiconductor laser mount manufactured for high-frequency driving), and the ground and the signal line are strip lines, and a signal of 10 Gbps. Can be passed. In FIG. 15, 42 is a surface emitting semiconductor laser mounting portion (FIG. 15B is an enlarged sectional view of this portion), 43 is a bonding wire, 44 is an Au electrode of a high-speed mount 41, and 45 is a metal ferrule 13 inserted. The other symbols are as described above.
[0083]
As shown in FIG. 5, a circular hole 45 into which a metal ferrule 13 of a surface emitting semiconductor laser module with a fiber can be inserted is formed in a portion 42 on which a surface emitting semiconductor laser (semiconductor laser chip) is mounted. The metal ferrule 13 is inserted into the hole 45 from the back side of the high-speed mount 41. The surface emitting semiconductor laser 10 is fitted into the metal ferrule 13 from the surface side of the high-speed mount 41 (the projection 18 of the surface emitting semiconductor laser 10 and the projection 14 of the metal ferrule 13 are fitted together).
[0084]
For this reason, the light of the surface emitting semiconductor laser 10 is extracted to the back side of the high-speed mount 41 through the optical fiber 24 of the surface emitting semiconductor laser module with a fiber. That is, the module of the present embodiment is a module that operates a surface emitting semiconductor laser at high speed in a surface emitting semiconductor laser that extracts light from the back side of the substrate. Since the high-speed mount 41 passes a signal of 10 Gbps, it is high-speed, and the surface emitting semiconductor laser 10 and the optical fiber 24 (metal ferrule 13) can be easily (i.e., inexpensively) aligned by passive alignment. Therefore, a high-speed and inexpensive module can be realized. In addition, light can be entered from the back side of the high-speed mount 41 through the optical fiber 24.
[0085]
In the above embodiment, the surface emitting semiconductor laser module with a fiber of the present invention is inserted into a dedicated semiconductor laser mount, but the surface emitting semiconductor laser module with a fiber of the present invention may be directly inserted into a cap of a high frequency connector. That is, a hole in which a ferrule can be inserted is formed in a cap of a high frequency connector, the ferrule is inserted from the front side of the cap, and a semiconductor laser mount is formed by a bonding wire from an electrode formed on a surface type optical semiconductor device (surface emitting semiconductor laser). The optical fiber may be inserted into the ferrule from the front side of the cap, and light may be extracted from the cap side of the high-frequency connector, or light may be entered.
[0086]
(Third embodiment)
FIG. 16 shows the structure of a wavelength-tunable surface emitting semiconductor laser module with a fiber according to a third embodiment of the present invention.
[0087]
It is said that surface emitting semiconductor lasers, particularly long-wavelength surface emitting semiconductor lasers, are difficult to form semiconductor mirrors with high reflectivity, and it is difficult to realize a current injection type surface emitting semiconductor laser. Here, in the surface emitting semiconductor laser, only the active layer, the lower mirror layer (lower semiconductor mirror), and the current injection electrode are formed, the dielectric multilayer mirror on the end face of the ferrule with a fiber facing the lower surface semiconductor mirror, And a surface emitting semiconductor laser. Further, a variable wavelength surface emitting semiconductor laser is realized by mechanically moving the position of the dielectric multilayer mirror by a piezo element.
[0088]
In FIG. 16, 51 is a dielectric multilayer mirror, 52 is a piezo element that expands and contracts when a voltage is applied (here, a cylindrical one is adopted), and 10 is an upper Bragg reflection mirror. A surface emitting semiconductor laser having an active layer 10b and a lower semiconductor mirror 10c, and the other symbols are as described above.
[0089]
The surface emitting semiconductor laser 10 of the third embodiment is also mounted on the tip (one end surface) of the metal ferrule 13 in the same manner as the surface emitting semiconductor laser 10 of the first embodiment. That is, the ring-shaped or pin-shaped protrusion 18 formed on the rear surface of the surface-emitting semiconductor laser 10 on the semiconductor substrate 12 side and the columnar protrusion 14 formed on one end surface of the metal ferrule 13 are fitted to each other, thereby generating surface emission. The center of the light emitting part (active layer 10b, lower semiconductor mirror 10c) of the semiconductor laser 10 and the center of the optical fiber 24 inserted into the metal ferrule 13 are passively aligned, and the light emitting part of the surface emitting semiconductor laser 10 and the above-mentioned This is a surface emitting semiconductor laser module with a fiber configured to be capable of optical coupling with the optical fiber 24.
[0090]
Then, this surface emitting semiconductor laser module with a fiber is provided as a first block, and the first block is inserted into the sleeve 31 from the right side of the sleeve 31 as indicated by an arrow A and fixed to the sleeve 31. The surface emitting semiconductor laser 10 is energized from the outside through the electrode wire 22, the bonding wire 21 and the pad electrode 20 of the surface emitting semiconductor laser 10, and through the metal ferrule 13 and the electrode 19 of the surface emitting semiconductor laser 10. Done.
[0091]
On the other hand, a ferrule with a fiber formed by inserting an optical fiber 33 into a ferrule 32 is provided as a second block. This second block is located on the sleeve 31 from the left side of the sleeve 31 as indicated by an arrow B, and is immediately adjacent to the sleeve 31. Is inserted. The second block (ferrule 32 and optical fiber 33) is not fixed to the sleeve 31 and can move in the axial direction of the sleeve 31, and a cylindrical piezo element 52 is bonded to the outer peripheral surface of the ferrule 32. Has been. The piezo element 52 is also bonded to the sleeve 31. Therefore, when the piezo element 52 expands and contracts in the axial direction of the sleeve 31 as indicated by an arrow C by applying a voltage, the second block (ferrule 32 and optical fiber 33) is moved to the arrow C along with the expansion and contraction of the piezo element 31. It moves in the axial direction as follows.
[0092]
A dielectric multilayer mirror 51 is formed on the end face of the optical fiber 33 of the second block. In FIG. 16, the dielectric multilayer mirror 51 is formed on the entire end face of the second block (the end face of the optical fiber 33 and the end face of the ferrule 31).
[0093]
As a result, oscillation occurs between the dielectric multilayer mirror 51 on the end face of the optical fiber 33 of the second block facing and the lower semiconductor mirror 10 c of the surface emitting semiconductor laser 10. That is, it is an external resonator type surface emitting semiconductor laser module. The oscillated light is coupled to the optical fibers 24 and 33 and output. Moreover, the second block (the ferrule 32 and the optical fiber 33) is mechanically moved by the piezo element 52, so that the dielectric multilayer film mirror 51 on the second block side and the lower semiconductor mirror 10c on the first block side. The oscillation wavelength of the surface emitting semiconductor laser 10 can be changed. When a voltage of about 10 V is applied to a piezoelectric element having a length of about 20 mm, the piezoelectric element extends about 1 μm. Therefore, by setting the distance between the mirrors 51 and 10c to about 5 to 10 μm, one oscillation wavelength can be obtained in a long wavelength band, for example, 1.55 μm band, and the distance (gap) is set to 1 μm by expansion and contraction of the piezoelectric element. By adjusting the degree, a wavelength variable width of about 100 nm can be obtained.
[0094]
As described above, according to the third embodiment, the alignment can be easily (inexpensive) by passive alignment, and the dielectric multilayer film mirror 51 is formed outside, and the piezo element 52 is used as the mirror. Since the distance between 51 and 10c can be changed, an inexpensive surface-emitting semiconductor laser module with a fiber having a variable wavelength in a long wavelength band (for example, 1.55 μm band) can be realized.
[0095]
In the above description, the second block (the metal ferrule 32 and the optical fiber 33) is moved by the piezo element 32. However, the present invention is not limited to this, and the piezo element is added to the first block (the metal ferrule 13). And the first block may be moved in the axial direction of the sleeve 31 with this piezo element.
[0096]
(Fourth embodiment)
In the above example, the ferrule-side projection or groove and the planar optical semiconductor device-side projection or groove are fitted. However, the entire planar optical semiconductor device is fitted in the groove or projection formed on the ferrule side. It may be complicated.
[0097]
That is, as shown in FIG. 17, the surface optical semiconductor device such as the surface emitting semiconductor laser 10 is centered on the light emitting portion, the light receiving portion, or the light input / output portion of the surface optical semiconductor device by processing means such as dicing or cleavage. A circular groove centered on the central axis of the ferrule so that the entire surface optical semiconductor device shaped into a square shape fits on one end surface of the ferrule 13. 15 is processed directly. Then, as indicated by an arrow in FIG. 18, the entire surface type optical semiconductor device such as the surface emitting semiconductor laser 10 is fitted into the groove 15 of the ferrule 13 so that the light emitting part, light receiving part or light of the surface type optical semiconductor device is obtained. The input / output unit is arranged so as to be positioned on the central axis of the ferrule, and an optical fiber is further inserted into the ferrule, so that the center of the light emitting unit, the light receiving unit or the optical input / output unit of the planar optical semiconductor device By passively aligning the center of the optical fiber, optical coupling between the light emitting part, the light receiving part or the light input / output part of the planar optical semiconductor device and the optical fiber becomes possible.
[0098]
【The invention's effect】
  As described above, in the present invention, protrusions or grooves are formed on one end surface of the ferrule and the epitaxial layer side surface or the semiconductor substrate side rear surface of the planar optical semiconductor device, and both are mounted so as to be fitted. Passive alignment can be performed so that the centers of the two coincide. In addition, by using a metal ferrule, the electrode of the planar optical semiconductor device can be drawn out through the metal ferrule. Further, if a ferrule with a fiber (first block) on which such a planar optical semiconductor device is mounted and another ferrule with a fiber (second block) are inserted into the sleeve from both sides, optical fibers at both ends of the sleeve A surface type optical semiconductor module with a fiber that can output light can be easily realized. Also, OutsideIf the partial mirror (dielectric multilayer mirror) is formed on the end face of the optical fiber of the second block facing the first block, an external resonator type variable wavelength surface emitting semiconductor laser module can be realized. And since all are passive alignment, it becomes possible to produce a module very cheaply.
[Brief description of the drawings]
FIG. 1 is a diagram showing a process of processing one end face of a metal ferrule in a first embodiment of the present invention.
FIG. 2 is a diagram showing a process of processing one end face of a metal ferrule in the first embodiment of the present invention.
FIG. 3 is a diagram showing a process of processing one end face of a metal ferrule in the first embodiment of the present invention.
FIG. 4 is a diagram showing a process of forming alignment protrusions on the back surface of the surface emitting semiconductor laser in the first embodiment of the present invention.
FIG. 5 is a diagram showing a process of forming alignment protrusions on the back surface of the surface emitting semiconductor laser in the first embodiment of the present invention.
FIG. 6 is a diagram showing a process of forming alignment protrusions on the back surface of the surface emitting semiconductor laser in the first embodiment of the present invention.
FIG. 7 is a diagram showing a process of forming alignment protrusions on the back surface of the surface emitting semiconductor laser in the first embodiment of the present invention.
FIG. 8 is a diagram showing a process of mounting a surface emitting semiconductor laser on one end face of a metal ferrule in the first embodiment of the present invention.
FIG. 9 is a diagram showing a process of mounting a surface emitting semiconductor laser on one end face of a metal ferrule in the first embodiment of the present invention.
FIG. 10 is a diagram showing a process of mounting a surface emitting semiconductor laser on one end face of a metal ferrule in the first embodiment of the present invention.
FIG. 11 is a diagram showing a process of mounting a surface emitting semiconductor laser on one end face of a metal ferrule in the first embodiment of the present invention.
FIG. 12 is an enlarged view of a connecting portion when the semiconductor substrate side rear surface of the surface emitting semiconductor laser and one end surface of the metal ferrule are connected to face each other in the first embodiment of the present invention.
FIG. 13 is an enlarged view of a connection portion showing an example in which the epitaxial layer side surface of the surface emitting semiconductor laser and one end surface of the metal ferrule are connected to face each other in the first embodiment of the present invention.
FIG. 14 is a view showing a modularized structure with a fiber in which a surface emitting semiconductor laser-mounted metal ferrule is placed in an insulating sleeve in the first embodiment of the present invention.
FIG. 15 is a diagram showing a structure in which a surface emitting semiconductor laser is mounted on a high-speed mount as a second embodiment of the present invention.
FIG. 16 is a diagram showing a structure of a wavelength-tunable surface emitting semiconductor laser module with a fiber according to a third embodiment of the present invention.
FIG. 17 is a view showing a structure of a surface emitting semiconductor laser module with a fiber according to a fourth embodiment of the present invention.
FIG. 18 is a diagram showing a configuration of a conventional semiconductor laser module with a fiber.
[Explanation of symbols]
10 Surface emitting semiconductor laser
11 Light emitting part
11a Upper Bragg reflection mirror
11b Active layer
11c Lower semiconductor mirror
12 Semiconductor substrate
13 Metal ferrule
14 protrusions
15 groove
16 groove
17 Solder
18 Protrusions
19 Electrode surface
20 Pad electrode
21 Bonding wire
22 Electrode wire
23 Small pieces of metal ferrule
24 optical fiber
24a core
25 Polyimide film
26 Semiconductor substrate on which protrusions are formed in advance
28 Substrate electrode
29 Light passage part
30A Backside laser beam
30B Laser light emitted from the surface
31 sleeve
32 Ferrule
33 Optical fiber
41 High-speed mount
42 Surface emitting semiconductor laser mounting part
43 Bonding wire
44 Au electrode
45 Ferrule insertion hole
51 Dielectric multilayer mirror
52 Piezo elements

Claims (15)

In a module in which an optical fiber is connected to a surface optical semiconductor device that emits light, receives light, or inputs and outputs light vertically to the surface of a semiconductor wafer such as a surface emitting semiconductor laser, a photodiode, a surface optical amplifier, and a surface optical gate. ,
On the surface on the epitaxial layer side or the back surface on the semiconductor substrate side of the planar optical semiconductor device, for alignment located on the circumference centered on the light emitting part, the light receiving part or the optical input / output part of the planar optical semiconductor device Forming protrusions or grooves,
And using the 1st ferrule and the small piece of the 2nd ferrule whose diameter is smaller than this 1st ferrule, the small piece of the 2nd ferrule is said 1st on the one end surface of the 1st ferrule. A protrusion located on the circumference centering on the central axis of the first ferrule is formed by bonding the central axis of the ferrule and the central axis of the small piece of the second ferrule in an aligned state. And
The surface of the planar optical semiconductor device having the projection or groove formed thereon is opposed to the surface of the first ferrule projection, and the projection or groove of the planar optical semiconductor device and the projection of the ferrule Are arranged so that the light emitting part, the light receiving part or the light input / output part of the planar optical semiconductor device is at the center of the first ferrule, and the optical fiber is inserted into the ferrule. ,
By passively aligning the center of the light emitting unit, the light receiving unit or the light input / output unit of the planar optical semiconductor device and the center of the optical fiber, the light emitting unit, the light receiving unit or the light of the planar optical semiconductor device. A surface-type optical semiconductor module with a fiber, characterized in that an optical coupling between an input / output unit and the optical fiber is possible. In the surface type optical semiconductor module with a fiber according to claim 1 ,
A protrusion or groove for alignment formed on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device,
A surface-type optical semiconductor module with a fiber, wherein the surface-type optical semiconductor device is formed by directly processing the surface on the epitaxial layer side or the back surface on the semiconductor substrate side by a technique such as etching. In the surface type optical semiconductor module with a fiber according to claim 1 ,
A protrusion or groove for alignment formed on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device,
A planar optical semiconductor module with a fiber, wherein an insulating layer such as polyimide provided on the epitaxial layer side surface or the semiconductor substrate side rear surface of the planar optical semiconductor device is processed by a technique such as etching. . In the surface type optical semiconductor module with a fiber according to claim 1 ,
A protrusion or groove for alignment formed on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device,
With a fiber characterized by being formed by processing another semiconductor or glass substrate bonded directly or via an adhesive layer to the semiconductor substrate surface of the planar optical semiconductor device by a technique such as etching Planar optical semiconductor module. In the surface type optical semiconductor module with a fiber according to claim 1 ,
A protrusion or groove for alignment formed on the epitaxial layer side surface or the semiconductor substrate side back surface of the planar optical semiconductor device,
The semiconductor substrate surface of the surface type optical semiconductor device, a semiconductor or glass or other substrate in which a protrusion or groove for alignment is previously formed by a technique such as etching, the light emitting portion of the surface type optical semiconductor device, The light emitting part, the light receiving part or the light input / output part and the protrusion or groove are arranged so that the light receiving part or the light input / output part is at the center of the protrusion or groove formed in advance on the other semiconductor or glass substrate. A surface-type optical semiconductor module with a fiber, which is formed by matching and bonding. In the surface type optical semiconductor module with a fiber according to any one of claims 1 to 5 ,
The ferrule is formed of a metal such as nickel, kovar, copper, stainless steel, and when the surface-type optical semiconductor device is mounted on the ferrule, the surface-type optical semiconductor device is formed with solder formed on one end surface of the ferrule. By electrically connecting, the first electrode of the planar optical semiconductor device is drawn out to the outside,
Further, a groove is provided on a side surface of the ferrule, and an electrode wire that is electrically insulated from the ferrule is disposed in the groove, and an alignment surface of the electrode wire and the ferrule in the planar optical semiconductor device is By connecting the second electrode formed on the opposite surface with a bonding wire,
A planar optical semiconductor module with a fiber, wherein the planar optical semiconductor device can be energized from the outside via the ferrule and the electrode wire. In the surface type optical semiconductor module with a fiber according to any one of claims 1 to 5 ,
The ferrule is formed of a metal such as nickel, kovar, copper, stainless steel, and when the surface optical semiconductor device is mounted on the ferrule, the surface optical semiconductor device is formed with solder formed on one end surface of the ferrule. Electrically connect,
Further, a groove is provided on a side surface of the ferrule, and an electrode wire that is electrically insulated from the ferrule is disposed in the groove, and the electrode wire is formed on an alignment surface of the ferrule in the planar optical semiconductor device. And connected to the second electrode,
When the alignment surface of the planar optical semiconductor device is the epitaxial layer side surface, the first electrode and the second electrode formed on the epitaxial layer side surface are respectively connected to the ferrule and the electrode. Pull out directly through the wire and
Alternatively, when the alignment surface of the planar optical semiconductor device is the back surface on the semiconductor substrate side, the first electrode and the second electrode formed on the epitaxial layer side surface are opened in the semiconductor substrate, respectively. By pulling out to the back side of the semiconductor substrate side through the through-hole type electrode formed by embedding a conductive material in the through-hole, and pulling out to the outside through the ferrule and the electrode wire,
A planar optical semiconductor module with a fiber, wherein the planar optical semiconductor device can be energized from the outside via the ferrule and the electrode wire. A surface type optical semiconductor module with a fiber according to any one of claims 1 to 7 is provided as a first block, the first block is inserted into the sleeve from one side of the sleeve, and another ferrule A ferrule with a fiber formed by inserting another optical fiber into the second block, and the second block is inserted into the sleeve from the opposite side of the sleeve;
By arranging the center of the light emitting unit, the light receiving unit or the light input / output unit of the planar optical semiconductor device included in the second block to coincide with the center of the optical fiber included in the second block,
A surface-type optical semiconductor module with a fiber, which is configured to enable optical coupling between the surface-type optical semiconductor device and the optical fiber. In the surface type optical semiconductor module with a fiber according to claim 8 ,
An optical element such as a gradient index lens is inserted into the sleeve so as to be positioned between the first block and the second block, and the first block and the first block are inserted by the optical element. A surface-type optical semiconductor module with a fiber, wherein the block is optically coupled to the block. In the surface type optical semiconductor module with a fiber according to claim 8 or 9 ,
The surface-type optical semiconductor device is a surface-emitting semiconductor laser;
The main output light from the surface-emitting semiconductor laser is extracted from either one of the optical fibers included in the first block or the second block, and the optical fiber included in the first block or the second block. A surface-type optical semiconductor module with a fiber, wherein the monitor light from the surface-emitting semiconductor laser is extracted from either one of the two. In the surface type optical semiconductor module with a fiber according to claim 8 or 9 ,
The surface-type optical semiconductor device is a surface-emitting semiconductor laser;
By introducing the pumping light for the surface emitting semiconductor laser through the optical fiber included in the first block or the second block, the surface emitting semiconductor laser is irradiated,
Surface-emitting light with a fiber, wherein the main output light from the surface-emitting semiconductor laser, or the main output light and the monitor light are extracted from an optical fiber included in the first block or the second block. Semiconductor module. In the surface type optical semiconductor module with a fiber according to any one of claims 8 to 11 ,
The surface-type optical semiconductor device is a surface-emitting semiconductor laser;
In this surface emitting semiconductor laser, all or part of the upper Bragg reflecting mirror is not formed, and a dielectric multilayer mirror is formed on the end face of the optical fiber of the second block,
Between the lower semiconductor mirror formed on the surface emitting semiconductor laser and the external dielectric multilayer mirror, the surface emitting semiconductor laser is oscillated by current injection or optical excitation,
Furthermore, a piezo element is bonded to the ferrule of the first block or the second block, and the lower block is formed by mechanically moving the first block or the second block in the axial direction of the sleeve with the piezo element. A surface-type optical semiconductor module with a fiber, wherein an oscillation wavelength of the surface-emitting semiconductor laser is made variable by changing a distance between a semiconductor mirror and the dielectric multilayer mirror. The surface-type optical semiconductor module with a fiber according to any one of claims 1 to 7 is provided as a first block and a second block, respectively.
By inserting the first block into the sleeve from one side of the sleeve, and inserting the second block into the sleeve from the opposite side of the sleeve,
The center of the light emitting unit, the light receiving unit, or the light input / output unit of the planar optical semiconductor device included in the first block is the light emitting unit, the light receiving unit, or the light input of the planar optical semiconductor device included in the second block. Arrange it so that it matches the center of the output section.
A surface-type optical semiconductor module with a fiber, which is configured to enable optical coupling between the surface-type optical semiconductor device and the optical fiber. In the surface type optical semiconductor module with a fiber according to claim 13 ,
An optical element such as a gradient index lens is inserted into the sleeve so as to be positioned between the first block and the second block, and the first block and the first block are inserted by the optical element. A surface-type optical semiconductor module with a fiber, wherein the block is optically coupled to the block. In the surface type optical semiconductor module with a fiber according to claim 13 or 14 ,
The surface optical semiconductor device of the first block is a surface emitting semiconductor laser, and the surface optical semiconductor device of the second block is a detector such as a photodiode;
A fiber-attached surface characterized in that the main output light of the surface-emitting semiconductor laser is extracted from the optical fiber of the first block and the monitor electrical output of the detector is extracted from the second block. Type optical semiconductor module.

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