JP2006084683A - Optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical module which satisfies the requirement that its electric field strength is less than 54dB μV/m at 1GHz at 3m apart from it and it does not radiate noise to the outside or does not receive the outside noise. <P>SOLUTION: In this optical module, the sleeve 9 is divided into three coaxial components, i.e. a lower metal ring 5, an insulation ring, and an upper metal lid 7 between the package 1 housing the optical element and the receptacle 60 to connect the ferrule of the external optical fiber. Those three components are connected together with their surfaces in contact together by pressing them in without using adhesives. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical module for detachably butting and coupling an optical element (a light emitting element and a light receiving element) to an optical fiber. When an optical module containing an optical element is coupled to an optical connector provided at the tip of an optical fiber, there are a receptacle type and a pigtail type. In the pigtail type, the optical element and the front end of the short optical fiber are fixed to face each other in the housing, and the other end of the fiber protrudes from the housing and is attached to another optical connector. The optical connector and an optical connector of another optical fiber can be coupled and detached. Therefore, in the case of the pigtail type, the optical fiber facing the optical element is fixed, and it is the external optical connector that is attached and detached.

  In the receptacle type, an optical element is provided in a housing having a cylindrical sleeve, and a ferrule at the tip of the optical fiber is inserted into the cylindrical sleeve to couple the optical fiber and the optical element oppositely. Many receptacle-type optical modules have already been used. In the case of the receptacle type, a package holding an optical element, a lens holder, a sleeve and the like are aligned and fixed in a two-dimensional direction. The package, lens holder, sleeve, etc. were all metal.

  However, in the case of an optical module incorporating a semiconductor laser, the frequency of the electric circuit that drives the semiconductor laser is increased, and radio waves are radiated into the space. In normal applications, radio waves can be emitted, but in special cases, it is now restricted that radio waves are emitted outside and cause noise to other devices. It is desirable to devise the structure of the optical module itself so as not to emit noise to the outside.

  There is an American standard called FCCP Part 15 for optical modules. This is shown in FIG. A table 43 is placed on the reference ground plane 42 in an anechoic chamber that is electromagnetically shielded from outside radio waves. An optical module 44 to be tested is fixed thereon. A support base 45 is placed at a location that is approximately a reference distance away from it. There is a holding rod 46 whose height is adjustable with respect to the support base 45, and an antenna 47 is fixed to the holding rod. The distance between the optical module 44 and the antenna 47 is set as a reference distance. The optical module is driven by current and radio waves flying from the optical module are received by the antenna, the electric field strength (dBμV / m) for each frequency is examined, and it must be below a certain reference value.

  The reference length is 10 m, and the limit of the electric field strength varies depending on the frequency. There are class A and class B. Although the reference length is 10 m, it requires a wide anechoic chamber and is converted to 3 m. When the frequency is low (10 kHz to 1 MHz), there is a difference of about 30 dB between 10 m and 3 m. When the frequency is 100 MHz to 10 GHz, there is a difference of about 20 dB. The conversion formula determines the relationship between the limit values in the case of 3 m and 10 m depending on the frequency. Next, class A and B limit values in terms of 3 m are shown.

Class B has a stronger demand. Therefore, attention is focused on Class B. The standard is that the electric field strength at 3 m is smaller than the above value, but since natural noise is lower than the above value, the noise value at the driving frequency in the case of a semiconductor laser or a light emitting diode is low. It becomes a problem. When driving a semiconductor laser or a light emitting diode with a drive frequency fc, radio waves of that frequency are generated from the drive circuit. The higher the frequency, the easier it is for radio waves to be emitted. Here, an example of driving a semiconductor laser at fc = 10.312 GHz is taken as an example.

  The antenna must receive 30 MHz to 18 GHz, and the field strength for each frequency must be examined. However, the problem is noise at the drive frequency fc. Above 960 MHz, the limit is 54 dBμV / m, and the electric field strength should be lower than this. However, this value is exceeded in the case of an optical transmission module made entirely of metal. So I can't meet the above criteria. It is an object of the present invention to provide an optical module that satisfies the above criteria.

  Since it is difficult to obtain an antenna capable of receiving such a wide range of signals, two types of antennas are used. The radio wave characteristics of the optical module were examined in a laboratory in which 30 MHz to 1 GHz was received with a bi-log antenna and 1 GHz to 18 GHz was received with a horn antenna.

Japanese Utility Model Publication No.4-130460 "Optical Receptacle Module"

  Patent Document 1 proposes a module in which an insulating member is inserted between a portion forming an outer shell of an optical element and a receptacle for holding an optical fiber. The purpose of this is to make it possible to use either a + 5V power supply or a -5V power supply without causing an optical element failure during welding by inserting an insulating member.

  The structure will be described with reference to FIG. The receptacle 60 includes a cylindrical receptacle 60 on which the ferrule can be inserted and removed, a cylindrical holder 58 following the receptacle, and cylindrical packages 55, 56, 57 that are fixed to the holder 58 and hold the optical element 50. The package is divided into upper and lower parts by an insulator, and an insulator ring 56 is inserted between the upper metal portion 57 and the lower metal portion 55.

  The insulator ring 56 bisects the package up and down. A metal lower portion 55 holds the optical element 50, and a metal upper portion 57 continues to the holder 58 and the receptacle 60.

  Therefore, the insulator ring 56 electrically insulates the optical element 50 from the receptacle 60. The receptacle 60 has holes 66 and 65 for inserting a ferrule with a fixed optical fiber tip. Furthermore, the hole 64 continues and the lens 63 is provided.

  Patent Document 1 aims to prevent an element from failing during welding and not to fail even if metal contacts during operation, and is not intended to satisfy the international standard FCCP Part 15. However, since no other appropriate literature was found, this was given as a conventional example.

  In Patent Document 1, an insulator 56 is inserted in the middle of an optical module package to electrically cut off the optical element 50 and the receptacle 60. It isolates the optical element 50 from the potential of the receptacle 60, prevents the optical element from failing during welding, can drive the optical element with either a + 5V power supply or a -5V power supply, contacts the metal during operation and shorts out The purpose is not to do that.

  The object of the present invention is to prevent noise from being transmitted to the outside. However, there is a common point in that an insulator is inserted between the receptacle and the optical element. Therefore, Patent Document 1 is cited. It seems that the receptacle of that structure is not used now. It may not be necessary to drive with a ± 5V power supply.

  Although the product of Patent Document 1 does not actually exist, if the difficulty of the receptacle is estimated, the package lower part 55, the insulating ring 56, and the package upper part 57 on which the light emitting elements are stacked are joined by joint surfaces 68 and 69 perpendicular to the optical axis. The The package lower portion 55, the insulating ring 56, and the package upper portion 57 are welded to the holder 58 via the welding surface 59. The holder 58 and the receptacle 60 are joined at a joining surface 62 perpendicular to the optical axis. These joining surfaces 68, 69, 62 are aligned and searched for an optimum position to be fixed. High degree of freedom in lateral positioning.

However, there are the following disadvantages.
(1) Strict assembly accuracy is required.
(2) The temperature characteristics are unstable.
(3) Low reliability.

The insulator 56 and the upper and lower metal portions 57 and 55 have different coefficients of thermal expansion due to temperature. The insulator 56 and the metal portions 57 and 55 expand and contract depending on the temperature. Since soldering and welding cannot be performed between the insulator and the metal, the joining surfaces 68 and 69 are joined with an adhesive. Adhesives are unreliable and can be removed by lateral forces.

  In addition, it is unclear whether the structure of Patent Document 1 can satisfy the FCCP Part 15 standard described above.

  An optical module of the present invention includes an optical element, a package that holds the optical element and includes a lens holder and a stem, a receptacle that detachably holds an optical fiber ferrule, and a sleeve that couples the receptacle and the package, The sleeve between the packages is divided into three parts in the vertical direction inside and outside, and metal parts are provided on the inside and outside of the top and bottom so that the insulating part is sandwiched between them. That is, the sleeve is composed of an upper metal portion, an inner insulating portion, and a lower metal portion, and the upper, middle, and lower metals, the insulating portion, and the metal portion are fitted in the inner and outer vertical directions so that the axes are equal. The lower metal portion of the sleeve was fitted into a package containing the optical element, and the upper metal portion of the sleeve was aligned with the receptacle in the direction perpendicular to the axis.

  Rather than dividing the package containing the optical element into three along the horizontal plane, the sleeve between the package and the receptacle is divided into three in the vertical direction inside and outside, and the fitting part is sandwiched between the insulating parts. The three members that constitute the sleeve, rather than bonding or welding, are fitted by press fitting. The sleeve consists of three members, but can be handled as a single part once they are fitted.

  Since an insulating member is inserted in the middle of the sleeve, an electrical signal is not transmitted to the receptacle. The receptacle is a member having a large volume and functions as an antenna. However, the drive frequency signal is blocked by the insulator and is not transmitted to the receptacle. The receptacle potential can be ground potential. It can be held at any DC potential instead of ground. Alternatively, a floating potential may be used. In any case, the drive frequency does not enter the receptacle. Therefore, the signal of the drive circuit of the light emitting element does not propagate around the optical module receptacle as an antenna. Therefore, when the electric field strength is measured at 3 m or 10 m ahead, the driving frequency is also less than the reference value. Therefore, it is possible to obtain an optical module that satisfies the above-mentioned FCCP Part 15 Class B standard.

  Since the three members constituting the sleeve are fitted by press fitting, alignment between the members is not necessary. Adhesive is also unnecessary. Reliability is improved because it is press-fit and no adhesive is used.

  Alignment in the xy direction is only required between the receptacle and the sleeve, which is the same as that of the conventional all metal type. The alignment part and the alignment work amount do not increase.

  The schematic structure of the optical module of the present invention will be described with reference to FIG. Although an optical element is attached to the upper surface of the stem 2 which is a metal disk, the illustration is omitted. The optical element is a comprehensive concept including a light emitting element and a light receiving element. The light emitting element includes a light emitting diode and a semiconductor laser. The light receiving element is a photodiode, an avalanche photodiode, a PIN photodiode, or the like.

  Since the noise is generated in the drive circuit of the light emitting element, the FCCPart 15 becomes a problem when the light emitting element is included. However, the same structure can be applied to the module of the light receiving element. In that case, a light receiving element module that is not easily affected by external noise can be obtained.

  A lenticular cylindrical lens holder 3 is welded above the stem 2. A package 1 is constituted by the stem 2 and the lens holder 3. An upper plate portion 26 is provided above the lens holder 3, and a hole 27 is formed in the center portion. The lens 4 is fixed to the hole 27. A sleeve 9 made of three members is provided on the outer upper side of the lens holder 3. The lower metal ring 5 is cylindrical and has the smallest inner diameter, the insulator ring 6 is cylindrical and has an intermediate inner diameter, and the upper metal lid 7 is disk and has the largest inner diameter. The reason why the upper metal lid 7 is disk-shaped is that it is necessary to place and align the receptacle on it and fix it. A cylindrical receptacle 8 is fixed on the upper metal lid 7 by welding.

  The triple sleeve 9 has metal rings 5 and 7 on the inside and outside, and has an insulating part 6 in the middle. There is a protrusion 28 on the outside of the lower metal ring 5, and the lower end of the insulator ring 6 is stopped by this. The protrusion 28 accurately regulates the pushing amount of the lower end of the insulator ring 6. The upper end of the insulator ring 6 comes into contact with the back surface of the upper metal lid 7 and stops. Therefore, the positional relationship in the vertical direction of the three sleeve members 5, 6, 7 is strictly determined. There is no room for adjustment and an accurate relationship can be maintained. A contact surface between the lower metal ring 5 and the insulator ring 6 is a press-fit surface 34. No adhesive is required. A contact surface between the insulator ring 6 and the upper metal lid 7 is also a press-fit surface 35. No adhesive is required.

  In FIG. 1, although the upper end height of the lower metal ring 5 and the lower end height of the upper metal lid 7 are drawn to be substantially the same, this indicates a limit height. The upper end height of the lower metal ring 5 may be equal to or higher than the lower end height of the upper metal lid 7. If the upper end height of the lower metal ring 5 is lower than the lower end height of the upper metal lid 7, there is a possibility that the insulator ring 6 is broken due to strong stress applied to the insulator ring 6. Since it is not preferable, the upper end height of the lower metal ring 5 should not be lower than the lower end height of the upper metal lid 7.

  The contact surface between the lens holder leg 25 and the stem 2 is a welding surface 32. A contact surface between the upper outer peripheral surface of the lens holder 3 and the inner peripheral surface of the lower metal ring 5 is a welding surface 33. A contact surface between the lower metal ring 5 and the insulator ring 6 is a press-fit surface 34. A contact surface between the insulator ring 6 and the upper metal lid 7 is a press-fit surface 35. The upper surface of the upper metal lid 7 and the lower surface of the receptacle 8 are welding surfaces 37.

  In the present invention, the sleeve 9 between the lens holder 3 and the receptacle is divided into a lower metal ring 5, an insulator ring 6, and an upper metal lid 7, and the insulator 6 is put in the middle. Therefore, electrical conduction is interrupted by the insulator ring 6. The optical element package and the receptacle are electrically insulated. If the entire module is made of metal, when a high-frequency drive current is passed through the optical element, the receptacle acts as an antenna, causing radio waves with the same frequency as the drive current to spread across the four sides. In the case of the invention, the receptacle does not become an antenna, and radio waves having a drive current frequency do not fly to the surroundings.

  FIG. 2 shows an entire optical module according to an embodiment of the present invention. Lead pins 22, 23 and 24 extend from below the stem 2 which is a metal disk. On the stem 2 is fixed a sleeve 9 in which three members, a cylindrical lower metal ring 5, an insulator ring 6, and an upper metal lid 7 are combined. A receptacle 10 is fixed on the upper metal lid 7. A ferrule with an optical fiber fixed can be inserted into the upper opening of the receptacle 10.

  State the dimensions. The length from the tip of the pin to the top bottom chamfer of the receptacle is 18.42 mm. The length of the receptacle portion 10 is 7.05 mm. The height of the triple sleeve 9 as a feature of the present invention is 2.60 mm. The diameter of the upper metal lid 7 is 5.20 mm. The outer diameter of the stem 2 is 3.90 mm. The diameter of the insulator ring 6 is 4.50 mm. The diameter of the upper opening of the receptacle 10 is 1.25 mm.

  FIG. 3 shows a cross-sectional view of the same optical module. The relationship between the three members shown in FIG. 1 and the sleeve is slightly different. The disc-shaped metal stem 2 is a pedestal to which the optical element 20 is attached. Here, the optical element 20 is an arbitrary light emitting element or light receiving element such as a semiconductor laser, a light emitting diode, a photodiode, an avalanche photodiode, or a PIN photodiode. A cylindrical lens holder 3 is fixed on the stem 2. The stem 2 and the lens holder 3 constitute a package 1.

  Resistance welding can be used for the welding surface 32. The lens 4 is attached to the lens hole 27 of the upper plate portion 26 of the lens holder 3. A sleeve 9 is welded to the upper outer peripheral surface of the lens holder 3. The sleeve 9 includes a lower metal ring 5, an insulator ring 6, and an upper metal lid 7. An insulator ring 6 is provided outside the lower metal ring 5, and an upper metal lid 7 is provided outside the insulator ring 6. The three members are combined by press fitting. Since there is a protrusion 28 on the outside of the lower metal ring 5, the depth of penetration of the insulator ring 6 is determined. The protrusion 28 is a positioning protrusion.

The insulator ring 6 should not be plastic. It must be combined by press-fitting and maintain the structure by itself. A highly rigid ceramic is suitable for the insulator. For example, zirconia (ZrO ₂ ). The lower metal ring 5 is, for example, SUS-SF20T. The upper metal lid is, for example, SUS-SF20T. The insulator ring 6 may be a complete ring as shown in FIG. However, if it is completely ring-shaped, the insulator ring may get wrinkled when it is press-fitted.

  If a part of the insulator ring 6 is cut out, no wrinkles will be generated by press-fitting. FIG. 12 shows an insulator ring 6 having a notch 49. However, if a part is cut out, the strength is slightly reduced. The upper metal lid 7 is preferably made of a ferromagnetic material. If the upper metal lid 7 is made of a ferromagnetic material, it can absorb a magnetic field component of radio waves and reduce noise. Naturally, since it is a metal, the electric field component is considerably absorbed by the eddy current, but the magnetic field component can also be absorbed, and radio wave leakage can be prevented more completely. Although many stainless steels have no magnetism, the above-mentioned SUS-SF20T is a ferromagnetic and conductive stainless steel.

  A cylindrical receptacle 10 is fixed on the upper metal lid 7. The receptacle 10 includes a stub holder 11, a housing 38, a zirconia sleeve 39, a stub 40, and an optical fiber 41. The stub 40 and the optical fiber 41 are polished obliquely to reduce the return light. A ferrule (not shown) that fixes the tip of the optical fiber for signal transmission is inserted into the front opening of the receptacle 10 and is brought into contact with the stub 40. Optical signals fly directly from the optical fiber end face to the optical fiber end face.

  If the optical element 20 is a light-emitting element, the light from the light-emitting element 20 is collected by the lens 4 at the end face of the optical fiber 41 and passes through the optical fiber 41 and further to an external optical fiber that is butt-fixed.

  When the optical element 20 is a light receiving element, an optical signal transmitted through an external optical fiber enters the upper end of the optical fiber 41 from the abutting surface, exits from the lower end, spreads out to free space, is condensed by the lens 4 and is emitted. Element 20 is entered.

  The hole 29 of the upper metal lid 7 is a hole through which light passes, and this is 0.5 mmφ in the embodiment. If it is too narrow, light does not pass easily and alignment becomes difficult, so the lower limit is about 0.2 mmφ. If it is too wide, radio waves may fly from this hole 29 and noise may be released to the front. Therefore, it is 1.2 mmφ at most. Therefore, the dimension of the hole 29 is 0.2 mmφ to 1.2 mmφ, and the optimum is 0.5 mmφ.

As described above, one of the objects of the present invention is to provide an optical module that is not easily affected by external noise emitted from a driving IC.
For example, a driving IC is often disposed immediately behind an optical device, such as an optical link. For example, when optical fiber communication is performed at 1 Gbps, the driving IC generates 1 GHz noise because the IC is driven with a 1 GHz clock. It is an object of the present invention to provide an optical module that is not affected by such noise.
8 is a bottom view of only the sleeve portion, FIG. 9 is a front view of only the sleeve portion, and FIG. 10 is a cross-sectional view. In this example, the upper metal lid 7 is a metal (magnetic metal) having an outer diameter of 5.20 mmφ. An insulator ring 6 (for example, zirconia) is inserted into the inside, and a lower metal ring 5 is inserted into the inside. The insulator ring 6 has chamfered ridges on the inside and outside of the top and bottom so that it can be easily press-fitted. The distance from the upper surface of the upper metal lid 7 to the lower end of the lower metal ring 5 (the thickness of the sleeve 9) is 2.60 mm. The thickness of the insulator ring 6 is 0.3 mm (outer diameter 4.50 mmφ, inner diameter 3.90 mmφ).

  Actually, noise measurement was performed at a distance of 3 m on the optical module according to the example of the present invention and the optical module of the conventional example without an insulating portion using the experimental apparatus of FIG.

  FIG. 4 is a graph showing the results of measuring the electric field strength of radio waves emitted by an optical module without an insulator (with a built-in semiconductor laser) using the measuring device in the anechoic chamber of FIG. The horizontal axis is frequency (GHz). The vertical axis represents the electric field strength (dBμV / m). According to the above-mentioned standard, if it is 1 GHz or more and Class B, it may be less than 54 dBμV / m. The limit is indicated by a one-dot chain line in the figure. The drive frequency of the semiconductor laser is fc = 10.312 GHz.

  From 1 GHz to 3 GHz, the electric field is 20-30 dBμV / m, which is the background. As the frequency increases, the electric field also increases, but it is 40 dBμV / m or less even up to 10 GHz. This is also a background. The noise intensity at the drive frequency fc = 10.312 GHz is a problem. The point marked with ○ is a component at fc = 10.312 GHz where the electric field vector is in the horizontal direction, and is 63.5 dBμV / m. This exceeds the reference value of 54 dBμV / m. The point marked with x is a component at fc = 10.312 GHz where the electric field vector is in the vertical direction, and is 60.4 dBμV / m. This exceeds the reference value. Therefore, the conventional all-metal type optical module having no insulating portion cannot satisfy the standard of less than 54 dBμV / m.

  FIG. 5 shows the result of measuring the noise generated by the optical module with the antenna placed at a distance of 3 m in the anechoic chamber in the same manner for the optical module (semiconductor laser) according to the embodiments described so far. The horizontal axis is the frequency (GHz) and indicates a range of 1 GHz to 18 GHz. The background noise is almost the same as the conventional example. It is 40 dBμV / m or less at 1 GHz to 10 GHz.

  The problem is noise at the drive frequency fc = 10.312 GHz. A circle indicates that there is an electric field vector component in the horizontal direction, which is 33 dBμV / m, which is below the background. The electric field strength in the vertical direction is 43 dBμV / m, which is also smaller than the reference value of 54 dBμV / m. This means that the frequency of the drive circuit of the semiconductor laser does not fly outside as a radio wave. That is, according to the present invention, it is possible to satisfy the Class B standard of FCCPart15.

  In the optical module, since the sleeve between the package and the receptacle is divided into three parts and an insulator ring is provided in part, in the case of the light emitting element module, the noise of the drive circuit does not come out to the outside. In the case of the light receiving element module, the influence of external noise can be suitably blocked.

  A lower metal ring 5, an insulator ring 6, and an upper metal lid 7 are combined in the vertical direction inside and outside, and are fixed to each other by press fitting. No adhesive is required and the bonding process can be simplified. If the adhesive is used, it will be eccentric and the position will go wrong, but if it is press fit, the positioning will be accurate. Since the metal rings 5 and 7 enter the upper and lower inside and outside of the insulator ring 6, the insulating ring does not break. If the protrusion 28 is attached to the lower metal ring 5 for positioning, the upper and lower positions are determined, which is more convenient. Since the upper metal lid 7 is made of a ferromagnetic material, radio waves can be absorbed thereby, and noise can be prevented from being scattered around.

The expanded sectional view of the stem of the optical module of this invention, a lens holder, and a sleeve part.

1 is an overall external view including a stem, a lens holder, and a sleeve of an optical module according to an embodiment of the present invention.

1 is an overall longitudinal sectional view including a stem, a lens holder, and a sleeve of an optical module according to an embodiment of the present invention.

In an experiment in which an optical module with a built-in semiconductor laser according to a conventional example of an all-metal type without an insulator is driven with an antenna separated by 3 m when driven at a frequency of 10.1212 GHz, the electric field strength measured for each frequency at 1 GHz to 18 GHz. Graph. Noise at 10.1212 GHz is 63.5 dBμV / m, which does not satisfy the standard (less than 54 dBμV / m).

In an experiment in which an optical module with a built-in semiconductor laser according to an embodiment of the present invention into which an insulator was inserted was received with an antenna separated by 3 m when driven at a frequency of 10.1212 GHz, the electric field strength measured for each frequency at 1 GHz to 18 GHz. Graph. Noise at 10.3112 GHz is 33 dBμV / m and 43 dBμV / m, which satisfies the standard (less than 54 dBμV / m).

Sectional drawing which shows the optical receptacle structure concerning the prior art example proposed in Japanese Utility Model Laid-Open No. 4-130460 “Optical Receptacle Module”.

The figure which shows the outline of the apparatus which places the optical module which should be tested on a table in an anechoic chamber, drives this, and measures the noise which an optical module produces with the antenna in the place 3 m away as a function of frequency.

The bottom view which shows the sleeve structure used for the optical module of this invention which combined three members which consist of a lower metal ring, an insulator ring, and an upper metal lid up and down inside and outside.

The front view which shows the sleeve structure used for the optical module of this invention which combined three members which consist of a lower metal ring, an insulator ring, and an upper metal lid up and down inside and outside.

The longitudinal cross-sectional view which shows the sleeve structure used for the optical module of this invention which combined three members which consist of a lower metal ring, an insulator ring, and an upper metal lid up and down inside and outside.

The top view of the insulator ring which is a perfect ring.

The top view of the insulator ring which is a ring which has a notch in part.

Explanation of symbols

1 Package 2 Stem
3 Lens holder
4 Lens
5 Lower metal ring
6 Insulator ring
7 Upper metal lid
8 Receptacle
9 Sleeve 10 Receptacle 11 Stub holder 20 Optical element 22 Pin
23 pins
24 pin
25 Lens holder legs
26 Upper plate
27 holes
28 ridges
29 holes
32 Welding surface
33 Welding surface
34 Press-fit surface
35 Press-fit surface
37 Welding surface
38 Housing 39 Zirconia sleeve
40 stubs
41 optical fiber
42 reference ground plane
43 tables
44 Optical module
45 Support stand
46 Holding rod
47 Antenna 49 Notch 50 Optical element 55 Lower metal part
56 Insulator ring
57 Metal upper part
58 Holder
59 Welding surface 60 Receptacle
62 Joining (welding) surface
63 lenses
64 holes
65 holes
66 holes
68 Joint surface
69 Bonding surface

Claims (10)

At least a stem on which the optical element is mounted, a cylindrical lens holder that accommodates the optical element fixed on the stem, a cylindrical lower metal ring that circumscribes the outer peripheral surface of the lens holder, and a circumscribed surface of the lower metal ring An insulator ring, a top metal lid made of a ferromagnetic material that has a hole circumscribed on the peripheral surface of the insulator ring, and an opening that is fixed on the top metal lid and can be attached to and detached from the ferrule of the external fiber An optical module comprising a receptacle, wherein a lower metal ring, an insulator ring, and an upper metal lid are fitted by press-fitting without using an adhesive. The optical module according to claim 1, wherein the insulator ring is made of a highly rigid ceramic. _2. The optical module according to claim 1, wherein the insulator ring is a sintered body mainly composed of zirconia (ZrO ₂ ). The optical module according to claim 3, wherein the insulator ring has a notch. The optical module according to any one of claims 1 to 4, wherein the lower metal ring has protrusions to regulate the amount of fitting of the insulator ring with respect to the lower metal ring. 6. The optical module according to claim 1, wherein the diameter of the hole of the upper metal lid is 0.2 mm to 1.2 mm. The optical module according to claim 1, wherein the optical element is a semiconductor laser. The optical module according to claim 1, wherein the optical element is a PIN photodiode. The optical module according to claim 1, wherein the optical element is an avalanche photodiode. The optical module according to claim 1, wherein optical fiber communication is performed using light in a wavelength range of 1.26 to 1.65 μm at a speed of 1 Gbps or more.

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