JP2011228468A - Multichannel optical transmission module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multichannel optical transmission module, capable of supplying satisfactory signals with small deterioration to the entire channels, when high-frequency signals exceeding 10 Gbps are handled.SOLUTION: The multichannel optical transmission module includes a laser array 3B, having a plurality of arrayed semiconductor laser elements, mounted inside a package 1. The multichannel optical transmission module also includes an aerial high-frequency wiring board 17 having a plurality of high-frequency wirings to supply the high-frequency signals. The aerial high-frequency wiring board 17 is disposed to be transversal between the mutually opposite side faces inside the package 1, at an upper position of the laser array 3B. Also, each high-frequency wiring is formed corresponding to a position on the plane of the plurality of semiconductor laser elements, and the high-frequency wiring is connected to each semiconductor laser element by a gold wire 13.

Description

  The present invention relates to a multi-channel optical transmission module that is a component of a large-capacity optical communication network.

  Conventionally, wire bonding using gold wires has been common as a method of electrical connection of high-frequency signal wiring.

  A conventional connection structure will be described with reference to FIG. FIG. 1 is a configuration diagram showing a configuration using a conventional connection structure in a single channel optical transmission module using a direct modulation DFB laser. In FIG. 1, reference numeral 1 is a package, 2 is an LD carrier, 3A is a DFB laser, 4A is a subcarrier, 5A is a first lens, 6 is a Peltier element, 9 is a second lens with an isolator, and 10 is a ferrule color. , 11 is a pigtail fiber, 12 is a high-frequency wiring board, 13 is a gold wire, and 15 is a high-frequency wiring board for external connection.

  Referring to the high-frequency signal wiring of the conventional single-channel optical transmission module shown in FIG. 1, the high-frequency signal that has entered the package 1 from the high-frequency wiring board 15 is connected by the high-frequency wiring board 12 and the gold wire 13. The DFB laser 3A is also connected by a gold wire 13. In this way, by pulling the high-frequency wiring board 12 to the immediate vicinity of the DFB laser 3A, the distance for using the gold wire 13 is shortened, and the device is devised to minimize the characteristic deterioration due to the inductance component of the gold wire 13. It was.

  FIG. 2 is a configuration diagram showing a configuration using the above-described conventional connection structure in a multi-channel optical transmission module using a 4-channel DFB laser array with a multiplexer. In FIG. 2, the same components as those shown in FIG. However, in FIG. 2, the code | symbol 3B has shown the DFB laser array with a multiplexer.

  As in the conventional single channel optical transmission module shown in FIG. 1, the high frequency signal that has entered the package 1 from the high frequency wiring board 15 is connected by the high frequency wiring board 12 and the gold wire 13, and the high frequency wiring board 12 and the DFB laser are connected. The array 3B is also connected by a gold wire 13. In this way, since the high frequency wiring board 12 is drawn as close as possible to the DFB laser array 3B, the length of the gold wire 13 connecting the both DFB lasers on the outer edge side of the DFB laser array 3B and the high frequency wiring board 12 is a single channel. It is the same as the time and is suppressed to about 0.5 mm. However, the length of the gold wire 13 that connects the two DFB lasers on the center side of the DFB laser array 3B and the high-frequency wiring board 12 is 1 mm or more when the interval between the DFB lasers is 0.5 mm, which is larger than that of the outer edge side. More than twice as long is required.

  For this reason, when high-speed electrical signals (high-frequency signals) exceeding 10 Gbps are handled, the signals are supplied to these DFB lasers in channels other than the two channels on the outer edge side of the DFB laser array 3B, that is, the channels on the center side of the DFB laser array 3B. There is a problem that a high frequency signal to be deteriorated due to an inductance component of the gold wire 13 and a problem that an electric crosstalk occurs between adjacent channels of the gold wire 13 and the waveform is deteriorated.

JP 2003-207693 A

  For a high-speed multi-channel optical transmission module, it is very important to supply a high-frequency signal to each channel while suppressing signal degradation as much as possible. However, the conventional technique has a problem that the high-frequency signal deteriorates because the chip size increases and the length of the gold wire increases as the number of channels increases.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a multi-channel optical transmission module capable of supplying a good signal with little deterioration to all channels when a high-frequency signal exceeding 10 Gbps is handled.

A multi-channel optical transmission module according to the first invention for solving the above-mentioned problems is as follows.
In a multi-channel optical transmission module in which a laser array in which a plurality of semiconductor laser elements are arranged is mounted inside a housing,
A first high-frequency wiring board having a plurality of high-frequency wirings for supplying a high-frequency signal;
The first high-frequency wiring board is disposed so as to cross between facing side surfaces in the housing at a position above the laser array, and
The high-frequency wiring is formed corresponding to the position on the plane of the plurality of semiconductor laser elements,
The high-frequency wiring and the semiconductor laser element are each connected by a gold wire.

A multi-channel optical transmission module according to a second invention for solving the above-mentioned problems is as follows.
In a multi-channel optical transmission module in which a laser array in which a plurality of sets of semiconductor laser elements and modulators that modulate the semiconductor laser elements are arranged is mounted inside a housing,
A first high-frequency wiring board having a plurality of high-frequency wirings for supplying a high-frequency signal;
The first high-frequency wiring board is disposed so as to cross between facing side surfaces in the housing at a position above the laser array, and
The high-frequency wiring is formed corresponding to the position on the plane of the plurality of modulators,
The high-frequency wiring and the modulator are each connected by a gold wire.

A multi-channel optical transmission module according to a third invention for solving the above-mentioned problems is as follows.
In the multi-channel optical transmission module according to the first invention,
The semiconductor laser element is a direct modulation DFB laser, and three or more direct modulation DFB lasers are arranged.

A multi-channel optical transmission module according to a fourth invention for solving the above-mentioned problems is as follows.
In the multi-channel optical transmission module according to the second invention,
The semiconductor laser element is a DFB laser, the modulator is an electroabsorption optical modulator, and three or more sets of the DFB laser and the electroabsorption optical modulator are arranged.

A multi-channel optical transmission module according to a fifth invention for solving the above-mentioned problems is
In the multi-channel optical transmission module according to the second invention,
The semiconductor laser element is a DFB laser, the modulator is a Mach-Zehnder modulator, and two or more sets of the DFB laser and the Mach-Zehnder modulator are arranged.

A multi-channel optical transmission module according to a sixth invention for solving the above-mentioned problems is as follows.
In the multi-channel optical transmission module according to any one of the third to fifth inventions,
The semiconductor laser element and the modulator are made of a III-V group compound semiconductor composed of Si or at least two kinds of elements of Al, Ga, In, As, P, and Sb. To do.

A multi-channel optical transmission module according to a seventh invention for solving the above-described problems is
In the multi-channel optical transmission module according to any one of the first to sixth inventions,
A multiplexer for multiplexing optical paths from the semiconductor element laser or the modulator is formed in the laser array, and the multiplexer is a multimode interference type multiplexer or an arrayed waveguide grating multiplexer. It is characterized by that.

A multi-channel optical transmission module according to an eighth invention for solving the above-mentioned problems is as follows.
In the multi-channel optical transmission module according to any one of the first to sixth inventions,
A multiplexer for multiplexing optical paths from the semiconductor element laser or the modulator is provided independently of the laser array, and the multiplexer is a multiplexer using a dielectric filter. And

A multi-channel optical transmission module according to a ninth invention for solving the above-mentioned problems is as follows.
In the multi-channel optical transmission module according to the seventh or eighth invention,
The material of the multiplexer is a group III-V compound semiconductor composed of at least two kinds of elements of SiO ₂ , Si, or Al, Ga, In, As, P, and Sb. .

A multi-channel optical transmission module according to a tenth invention for solving the above-mentioned problems is
In the multi-channel optical transmission module according to any one of the first to ninth inventions,
A second high-frequency wiring board that relays between the external wiring and the first high-frequency wiring board is provided on each side surface facing the inside of the housing, and the top surfaces of the two second high-frequency wiring boards are high. The first high-frequency wiring board is fixed to the upper surfaces of the two second high-frequency wiring boards by arranging the height higher than the height of the upper surface of the laser array.

A multi-channel optical transmission module according to an eleventh invention for solving the above-mentioned problems is
In the multi-channel optical transmission module according to any one of the first to tenth inventions,
The material of the first high-frequency wiring board and the second high-frequency wiring board is any one of aluminum oxide, aluminum nitride, glass epoxy resin, and resin.

A multi-channel optical transmission module according to a twelfth invention for solving the above-mentioned problems is
In the multi-channel optical transmission module according to any one of the first to eleventh inventions,
The wiring shape of the first high frequency wiring board and the second high frequency wiring board is any one of a GND coplanar line, a microstrip line, a differential coplanar line, and a differential microstrip line. The wiring material of the first high-frequency wiring board and the second high-frequency wiring board is a metal composed of at least one element of Au, Pt, Ag, Al, Ti, Ni, and Cu.

  According to the present invention, when a high frequency signal exceeding 10 Gbps is handled, a multi-channel optical transmission module with little signal deterioration can be realized.

It is a block diagram which shows the single channel optical transmission module using the conventional connection structure, (a) is a top view, (b) is a side view. It is a block diagram which shows the multichannel optical transmission module using the conventional connection structure, (a) is a top view, (b) is a side view. It is a block diagram which shows an example (Example 1) of embodiment of the multichannel optical transmission module which concerns on this invention, (a) is a top view, (b) is a side view. FIG. 4 is a top view showing an aerial high-frequency wiring board of the multi-channel optical transmission module shown in FIG. 3. It is a block diagram which shows the experiment system for aligning the 1st lens of the multichannel optical transmission module shown in FIG. It is a block diagram which shows the experimental system for aligning the 2nd lens and pigtail fiber of the multichannel optical transmission module shown in FIG. It is a block diagram which shows the experimental system for eye pattern measurement of the multichannel optical transmission module shown in FIG. 2, FIG. It is a block diagram which shows the experimental system for bit error rate measurement of the multi-channel optical transmission module shown in FIG. 2, FIG. It is a block diagram which shows another example (Example 2) of embodiment of the multichannel optical transmission module which concerns on this invention, (a) is a top view, (b) is a side view. FIG. 10 is a top view showing an aerial high-frequency wiring board of the multi-channel optical transmission module shown in FIG. 9. It is a block diagram which shows the experimental system for aligning the 1st lens array of the multichannel optical transmission module shown in FIG. It is a block diagram which shows the experimental system for mounting the dielectric filter multiplexer of the multichannel optical transmission module shown in FIG. FIG. 10 is a configuration diagram showing an experimental system for eye pattern measurement of the multi-channel optical transmission module shown in FIG. 9. FIG. 10 is a configuration diagram illustrating a conventional multi-channel optical transmission module using a connection structure, which is a comparative example of the multi-channel optical transmission module illustrated in FIG. 9, and (a) is a top view and (b) is a side view. . It is a block diagram which shows the experimental system for bit error rate measurement of the multichannel optical transmission module shown in FIG. 9, FIG. It is a block diagram which shows another example (Example 3) of embodiment of the multichannel optical transmission module which concerns on this invention, (a) is a top view, (b) is a side view. FIG. 17 is a top view showing an aerial high-frequency wiring board of the multichannel optical transmission module shown in FIG. 16. It is a block diagram which shows the experimental system for aligning the 1st lens of the multichannel optical transmission module shown in FIG. FIG. 17 is a configuration diagram showing a multi-channel optical transmission module using a conventional connection structure, which is a comparative example of the multi-channel optical transmission module shown in FIG. 16, wherein (a) is a top view and (b) is a side view. . It is a graph which shows the wire length dependence of a frequency characteristic.

  In the conventional multi-channel optical transmission module, since the high frequency wiring board is disposed on the LD carrier, the high frequency wiring board is not disposed above the laser array.

  On the other hand, in the multi-channel optical transmission module according to the present invention, the high frequency wiring board is placed on the laser array by installing the high frequency wiring board so as to cross between the facing side surfaces inside the package. It is arranged to straddle. As a result, it is possible to draw the high-frequency wiring in the high-frequency wiring board up to just above each channel of the laser array. And when connecting between each channel and each high frequency wiring with the gold wire by wire bonding, it becomes possible to connect in all the channels by the shortest possible distance (about 0.6 mm at the longest).

  With such a configuration, it is possible to minimize the degradation of the high frequency characteristics due to the inductance component, and when handling a high frequency signal exceeding 10 Gbps, multi-channel optical transmission that supplies a good signal with little signal degradation to all channels A module can be realized.

  Some of the embodiments of the multi-channel optical transmission module according to the present invention will be described below. The following examples are some examples for explaining the present invention, and various modifications can be made without departing from the gist of the present invention.

(1. Configuration)
FIG. 3 is a configuration diagram showing the multi-channel optical transmission module of the present embodiment, FIG. 3 (a) is a top view thereof, and FIG. 3 (b) is a side view thereof. FIG. 4 is a top view of an aerial high-frequency wiring board described later.

  The multi-channel optical transmission module according to the present embodiment is provided in the package 1 serving as a housing thereof, a Peltier element 6 for cooling a laser array 3B described later, and an upper surface of the Peltier element 6. An LD carrier 2 on which the laser array 3B and a first lens 5A, which will be described later, are arranged, an LD carrier 2 provided on the upper surface of the LD carrier 2, and a subcarrier 4A on which the laser array 3B is arranged; And a first lens 5A for condensing the laser beam from the laser array 3B. With such a configuration, the laser array 3 </ b> B is mounted inside the package 1.

  Further, on the outside of one side surface of the package 1, the laser light collected by the first lens 5 </ b> A is collected, and a second lens 9 that enters the pigtail fiber 11 described later, and a ferrule collar that holds the pigtail fiber 11. 10 and a pigtail fiber 11 that propagates laser light from the laser array 3B to the outside.

  In the present embodiment, a 4-channel DFB laser array with a multiplexer is used as the laser array 3B serving as a multi-channel optical transmission array device. Specifically, in the laser array 3B, a direct modulation DFB laser is used as a semiconductor laser element, and an arrayed waveguide grating multiplexer (hereinafter referred to as an AWG multiplexer) is used as a multiplexer. On the InP substrate, four direct modulation DFB lasers are arranged and integrated, and an AWG multiplexer that multiplexes optical paths from the respective direct modulation DFB lasers is integrated. The multiplexer may be a multimode interference multiplexer (MMI multiplexer) shown in Example 3 described later.

In the laser array 3B, the channel spacing was 500 μm, and the wavelength of each channel was 1295 nm, 1300 nm, 1305 nm, and 1310 nm. The data rate is 25 Gbps, Non Return to ZERO (hereinafter referred to as NRZ), and a pseudo-random signal (hereinafter referred to as PRBS) supplies a high frequency signal of [2 ³¹ -1] to each channel.

  A high-frequency wiring board is provided on a side surface facing the inside of the package 1 across the laser array 3B for relaying between the wiring outside the package 1 and an aerial high-frequency wiring board 17 (first high-frequency wiring board) described later. 16 (second high-frequency wiring board) is provided, and an aerial high-frequency wiring board 17 is fixed to the upper surface of the relay high-frequency wiring board 16 so as to bridge between the two relay high-frequency wiring boards 16. . The relay high-frequency wiring board 16 is arranged such that the position of the upper surface thereof is higher than the position of the upper surface of the laser array 3B. As a result, the aerial high-frequency wiring board 17 is formed as shown in FIG. When viewed from the laser array 3 </ b> B, the laser array 3 </ b> B is installed at an air position above the laser array 3 </ b> B and crosses between the facing side surfaces inside the package 1.

  As shown in FIG. 4, the aerial high-frequency wiring board 17 has high-frequency wirings 17a for four channels and ground lines 17b adjacent to the high-frequency wirings 17a, and has a wiring shape of a GND coplanar line. In this embodiment, the material of the aerial high-frequency wiring board 17 itself is aluminum nitride, and the material of the high-frequency wiring 17a and the ground line 17b is Au. Each high-frequency wiring 17a can supply a high-frequency signal exceeding 10 Gbs, and is formed corresponding to the position on the plane of each direct modulation DFB laser, more specifically, the position on the plane of the electrode pad of each direct modulation DFB laser. It is.

  In the present embodiment, the aerial high-frequency wiring board 17 is disposed using the relay high-frequency wiring board 16, but crosses between the facing side surfaces inside the package 1 at a position above the laser array 3 </ b> B. Thus, any structure may be used as long as the aerial high-frequency wiring board 17 can be disposed. For example, a support portion higher than the upper surface of the laser array 3B may be provided on the side surface facing the package 1, and the aerial high-frequency wiring board 17 may be disposed on the upper surface so as to cross between the support portions.

  Since the aerial high-frequency wiring board 17 is installed at an aerial position above the laser array 3B, each high-frequency wiring 17a is formed to a position immediately above the directly modulated DFB laser of each channel, that is, to the nearest position. Can do. Accordingly, when the direct modulation DFB laser of each channel and the high-frequency wiring 17a are connected by wire bonding using the gold wire 13, it is possible to connect at a distance as short as possible. As a result, the length of the gold wire 13 can be suppressed to about 0.6 mm even if it is long in all channels, and when a high-frequency signal exceeding 10 Gbps is handled, a good signal with little deterioration is applied to all channels. Can be supplied. In addition, since the interval between the gold wires 13 is the interval between the channels, the interval can be increased as compared with the conventional case, and the occurrence of electrical crosstalk can be suppressed.

  For reference, FIG. 20 shows a graph of the dependency of the frequency characteristics on the wire length. This is a simulation of the frequency response when the inside of the DFB laser is represented by an equivalent circuit and a terminal resistance of 40Ω (50Ω in combination with the parasitic resistance of the DFB laser) and the inductance component of the wire are placed in series in the equivalent circuit. It is. In this simulation, the optical / electrical conversion of the DFB laser is not taken into consideration. As can be seen from the graph of FIG. 20, if the wire length can be suppressed to 0.5 mm, the 3 dB band goes to around 30 GHz (see thick line), but when the wire length becomes 1 mm, the 3 dB band cuts off 20 GHz, and 20 Gbps. It becomes difficult to transmit the signal exceeding (see thin line). From this simulation result, it can be seen that the present invention is effective for high-frequency signals of 10 Gbps or more.

  In this embodiment, four directly modulated DFB lasers are arranged in the laser array. However, if three or more directly modulated DFB lasers are arranged in the laser array, the application of this embodiment The above effects are achieved. In other words, in the conventional connection structure, when three or more directly modulated DFB lasers are arranged in the laser array, the length of the gold wire to the directly modulated DFB laser excluding the outer edge side becomes long. This is because the length can be suppressed by applying the embodiment.

(2. Principle of operation)
In the present embodiment, how to supply a high frequency signal to each channel of the laser array 3B will be described.

  A high-frequency signal that has entered the package 1 from the relay high-frequency wiring board 16 enters the aerial high-frequency wiring board 17 via the gold wire 13 and further passes through the gold wire 13 to each directly modulated DFB laser of the laser array 3B. Supplied. The signals converted into light by the laser array 3B are combined into one waveguide through an AWG multiplexer and output. The output light is condensed by the first lens 5 </ b> A and the second lens 9 and coupled to the pigtail fiber 11.

(3. Assembly process)
The procedure for producing the multi-channel optical transmission module of this example is shown below.

  First, the laser array 3B is mounted on the subcarrier 4A. Next, the subcarrier 4A is mounted on the LD carrier 2. Further, the Peltier element 6 is mounted inside the package 1, and the relay high-frequency wiring board 16 is mounted on the opposite side surface inside the package 1 and higher than the upper surface of the laser array 3B.

  Then, the first lens 5A is aligned using the experimental system shown in FIG. Specifically, a current of about 50 mA is supplied to any one channel of the direct modulation DFB laser of the laser array 3B using the DC power supply 22 and the DC probe 21. In this state, the CCD camera 24 is used to confirm the beam shape of the laser beam output from the laser array 3B, and the first beam shape and position of the laser beam are not changed at any position in the light traveling direction. The first lens 5A is aligned, and the first lens 5A is fixed to the LD carrier 2 by welding with an yttrium / aluminum / garnet laser (hereinafter referred to as YAG laser) 23.

  Thereafter, the LD carrier 2 is mounted on the Peltier element 6 mounted on the package 1. At this time, the aerial high-frequency wiring board 17 is temporarily mounted on the relay high-frequency wiring board 16 so that the positions of the electrode pads of each direct modulation DFB laser of the laser array 3B and the positions of the high-frequency wirings 17a of the aerial high-frequency wiring board 17 are matched. Next, the mounting position of the LD carrier 2 is adjusted. Next, the temporarily mounted aerial high-frequency wiring board 17 is fixed on the relay high-frequency wiring board 16. Then, the fixed aerial high-frequency wiring board 17, the relay high-frequency wiring board 16, and the laser array 3B are connected by a gold wire 13 by wire bonding.

  Finally, the second lens 9 and the pigtail fiber 11 are aligned using the experimental system shown in FIG. Specifically, the DC power supply 22 is used to supply a current of about 50 mA to an arbitrary channel of the direct modulation DFB laser of the laser array 3B, and in this state, the power entering the optical power meter 25 is maximized. The second lens 9 and the pigtail fiber 11 are aligned, and the second lens 9, the ferrule collar 10, and the pigtail fiber 11 are fixed by welding with the YAG laser 23. The multi-channel optical transmission module is thus completed.

(4. Characteristics)
An experimental system for eye pattern measurement is shown in FIG. The configuration of this experimental system will be briefly described. The multi-channel optical transmission module 31 is connected to one end of the optical fiber 32, and the other end of the optical fiber 32 is connected to the optical demultiplexer 33. The optical demultiplexer 33 is connected to a photodetector 34 for detecting laser light from the multi-channel optical transmission module 31, and the multi-channel optical transmission module 31 is connected to a pulse pattern generator 35, and further, the photodetector. A sampling oscilloscope 36 is connected to 34. Therefore, the laser light of the multi-channel optical transmission module 31 output based on the signal of the pulse pattern generator 35 is detected by the photodetector 34, and the detected laser light is analyzed by the sampling oscilloscope 36.

  For comparison, the conventional multi-channel optical transmission module shown in FIG. 2 was also measured at the same time. In this comparative measurement, the chip temperature was constant at 25 ° C., the bias current of the direct modulation DFB laser was 50 mA, and the amplitude of the input signal was 3.0 Vpp. In this comparative measurement, the conventional multi-channel optical transmission module had an extinction ratio of 4.0 dB, whereas the multi-channel optical transmission module of this example had an extinction ratio of 4.8 dB.

  When the bias current of 50 mA and the input signal amplitude of 3.0 Vpp are applied simultaneously for the four channels, the conventional multi-channel optical transmission module has an extinction ratio of 3.0 dB. In the optical transmission module, an extinction ratio of 4.5 dB was obtained.

  An experimental system for bit error rate measurement is shown in FIG. Next, using this experimental system, the code error rate characteristic (hereinafter referred to as BER characteristic) was measured. The configuration of this experimental system will be briefly described. The multi-channel optical transmission module 31 is connected to one end of the optical fiber 32, and the other end of the optical fiber 32 is connected to the optical demultiplexer 33. The optical demultiplexer 33 is connected to a photo detector 34 for detecting laser light from the multi-channel optical transmission module 31, and the multi-channel optical transmission module 31 is connected to a pulse pattern generator 35, and the photo detector 34 is connected to an error detector 37 via an optical variable attenuator 39. Therefore, the laser light of the multi-channel optical transmission module 31 output based on the signal of the pulse pattern generator 35 is detected by the photodetector 34, and the detected laser light is analyzed by the error detector 37.

  Here, both the conventional multi-channel optical transmission module and the multi-channel optical transmission module of the present embodiment were able to confirm error-free operation in each channel. In addition, the minimum light receiving sensitivity of channel 2 (second channel from the top in FIG. 3A) during simultaneous operation of all channels is -3 dBm compared to the conventional multi-channel optical transmission module. In the multi-channel optical transmission module of the example, it was -4.1 dBm.

  From the above, it has been clarified that a multi-channel optical transmission module with little signal deterioration can be realized when a high-frequency signal exceeding 10 Gbps is handled.

(1. Configuration)
FIG. 9 is a block diagram showing the multi-channel optical transmission module of the present embodiment, FIG. 9A is a top view thereof, and FIG. 9B is a side view thereof. FIG. 10 is a top view of an aerial high-frequency wiring board described later. In the multi-channel optical transmission module of the present embodiment, the same reference numerals are given to the same components as those of the multi-channel optical transmission module described in the first embodiment.

  The multi-channel optical transmission module of this embodiment is provided with a package 1 serving as a housing, and an EADFB laser array 3C, a first lens array 5B, and a dielectric filter multiplexer, which will be described later, on the upper surface thereof. 7 and the like, a subcarrier 4B with wiring provided on the upper surface of the LD carrier 2, and an EADFB laser array 3C disposed on the upper surface, a plurality of sets of semiconductor laser elements and modulators thereof The integrated EADFB laser array 3C, the first lens array 5B for condensing the plurality of laser beams from the EADFB laser array 3C, and the dielectric filter combination for combining the laser beams collected by the first lens array 5B And a corrugator 7. With such a configuration, the EADFB laser array 3 </ b> C is mounted inside the package 1.

  Further, on the outside of one side surface of the package 1, the laser light combined by the dielectric filter multiplexer 7 is collected, and the second lens 9 that enters the pigtail fiber 11 described later and the pigtail fiber 11 are held. A ferrule collar 10 and a pigtail fiber 11 for propagating laser light from the EADFB laser array 3C to the outside are provided.

  In this embodiment, a 4-channel electroabsorption optical modulator integrated DFB laser array is used as the EADFB laser array 3C, which is an array device for multi-channel optical transmission. Specifically, in the EADFB laser array 3C, a DFB laser is used as a semiconductor laser element (hereinafter referred to as a DFB laser unit), and an electroabsorption modulator (hereinafter referred to as an EA unit) is used as a modulator. And four sets of DFB laser parts and EA parts are arranged and integrated on the InP substrate. As the multiplexer, a dielectric filter is used, and is not integrated in the EADFB laser array 3C, but provided independently. Therefore, the dielectric filter multiplexer 7 provided outside the EADFB laser array 3C multiplexes the optical path from each EA section.

In the EADFB laser array 3C, the channel spacing was 500 μm, and the wavelength of each channel was 1295 nm, 1300 nm, 1305 nm, and 1310 nm when the chip temperature was 25 ° C. The PRBS supplies a high frequency signal of [2 ³¹ -1] to each channel with a data rate of 25 Gbps and NRZ.

  Further, on the facing side surface inside the package 1 across the EADFB laser array 3C, a relay high frequency is provided for relaying between the wiring outside the package 1 and an aerial high frequency wiring board 18 (first high frequency wiring board) described later. A wiring board 16 is provided, and an aerial high-frequency wiring board 18 is fixed on the upper surface of the relay high-frequency wiring board 16 so as to bridge between the two relay high-frequency wiring boards 16. The relay high-frequency wiring board 16 is arranged such that the position of the upper surface thereof is higher than the position of the upper surface of the EADFB laser array 3C. As a result, the aerial high-frequency wiring board 18 is as shown in FIG. In addition, when viewed from the EADFB laser array 3C, the EADFB laser array 3C is installed at an air position above the EADFB laser array 3C and crosses between the facing side surfaces inside the package 1.

  As shown in FIG. 10, the aerial high-frequency wiring board 18 has high-frequency wirings 18a for four channels and a ground line (not shown) formed on the back side thereof, and has a wiring shape of a microstrip line. Yes. In this embodiment, the material of the aerial high-frequency wiring board 18 itself is aluminum oxide, and the material of the high-frequency wiring 18a is Cu. Each high-frequency wiring 18a can supply a high-frequency signal exceeding 10 Gbs, and is formed corresponding to the position on the plane of each EA portion, more specifically, the position on the plane of the electrode pad of each EA portion.

  In the present embodiment, the relay high frequency wiring board 16 is also used to arrange the aerial high frequency wiring board 18, but at the position above the EADFB laser array 3 </ b> C, it crosses between the facing side surfaces inside the package 1. As long as the aerial high-frequency wiring board 18 can be disposed, any structure may be used. For example, the structure etc. which provide a support part like Example 1 may be sufficient.

  Since the aerial high-frequency wiring board 18 is installed at an aerial position above the EADFB laser array 3C, each high-frequency wiring 18a can be formed to a position immediately above the EA portion of each channel, that is, to the nearest position. it can. Therefore, when the EA portion of each channel and the high-frequency wiring 18a are connected by wire bonding using the gold wire 13, it is possible to connect at the shortest possible distance. As a result, the length of the gold wire 13 can be suppressed to about 0.6 mm at all in all channels, and as described in FIG. 20 described above, when handling a high-frequency signal exceeding 10 Gbps, A good signal with little deterioration can be supplied to all channels. In addition, since the interval between the gold wires 13 is the interval between the channels, the interval can be increased as compared with the conventional case, and the occurrence of electrical crosstalk can be suppressed.

  In this embodiment, four sets of the DFB laser unit and the EA unit are arranged in the laser array. However, as long as three or more sets of the DFB laser unit and the EA unit are arranged in the laser array. By applying the present embodiment, the above effects can be achieved. In other words, in the conventional connection structure, when three or more pairs of the DFB laser part and the EA part are arranged in the laser array, the length of the gold wire to the EA part excluding the outer edge side becomes long. This is because the length can be suppressed by applying this embodiment.

(2. Principle of operation)
In the present embodiment, how to supply a high-frequency signal to each channel of the EADFB laser array 3C will be described.

  A high-frequency signal that has entered the package 1 from the relay high-frequency wiring board 16 enters the aerial high-frequency wiring board 18 via the gold wire 13 and is further supplied to each EA portion of the EADFB laser array 3C via the gold wire 13. Is done. The signal converted into light by the DFB laser unit of the EADFB laser array 3C and modulated by the EA unit becomes collimated light through the first lens array 5B, and passes through the dielectric filter multiplexer 7 into one optical path. Combined and output. The output light is collected by the second lens 9 and coupled to the pigtail fiber 11.

(3. Assembly process)
The procedure for producing the multi-channel optical transmission module of this example is shown below.

  First, the EADFB laser array 3C is mounted on the subcarrier 4B with wiring. Next, after the subcarrier 4B is mounted on the LD carrier 2, the DFB laser portion of the EADFB laser array 3C and the subcarrier 4B with wiring are connected by a gold wire by wire bonding. Further, the relay high-frequency wiring board 16 is mounted on a side surface facing the inside of the package 1 and higher than the upper surface of the EADFB laser array 3C.

  Then, the first lens array 5B is aligned using the experimental system shown in FIG. Specifically, about 70 mA of current is supplied to each of the four channels of the DFB laser section of the EADFB laser array 3C using the DC power supply 22 and the DC probe 21. In this state, the CCD camera 24 is used to check the beam shape of the laser light output from the EADFB laser array 3C, and the beam shape and position of the laser light output from each channel are the same regardless of the channel. The first lens array 5B is aligned so that it does not change at any position in the traveling direction, and the first lens array 5B is fixed to the LD carrier 2 by welding with the YAG laser 23.

  Next, using the experimental system shown in FIG. 12, the dielectric filter multiplexer 7 is mounted on the LD carrier 2 so that the laser beams output from the four channels are combined into one optical path. . Specifically, first, the laser beam output from each of the channels 2 and 3 (two channels in the center in FIG. 12) of the EADFB laser array 3C is viewed in the CCD camera 24 in which position in the light traveling direction. However, the dielectric filters 7-4 and 7-5 are mounted so as to be in the same place. Next, the laser light output from the channel 1 (the upper channel in FIG. 12) passes through the dielectric filter 7-4 and is seen at the CCD camera 24, and becomes the same place at any position in the light traveling direction. Thus, the dielectric filter 7-3 is mounted. Similarly, the laser light output from the channel 4 (the lower channel in FIG. 12) passes through the dielectric filter 7-5 and is seen by the CCD camera 24 at the same position in any position in the light traveling direction. As shown, a dielectric filter 7-6 is mounted.

  Then, the laser light output from the channels 3 and 4 (the two lower channels in FIG. 12) is seen in the CCD camera 24 so that the position is the same at any position in the light traveling direction. Mount body filter 7-2. Finally, the laser beams output from the channels 1 and 2 (the upper two channels in FIG. 12) are the same at any position in the light traveling direction as viewed by the CCD camera 24 through the dielectric filter 7-2. The dielectric filter 7-1 is mounted so as to be in the place. As described above, the dielectric filter multiplexer 7 that can combine the optical paths into one is mounted.

  Thereafter, the LD carrier 2 is mounted in the package 1. At this time, the aerial high-frequency wiring board 18 is temporarily mounted on the relay high-frequency wiring board 16 so that the position of the electrode pad of each EA portion of the EADFB laser array 3C matches the position of each high-frequency wiring 18a of the aerial high-frequency wiring board 18. The mounting position of the LD carrier 2 is adjusted. Next, the temporarily mounted aerial high-frequency wiring board 18 is fixed on the relay high-frequency wiring board 16. Then, the fixed aerial high-frequency wiring board 18, the relay high-frequency wiring board 16, and the EADFB laser array 3C are connected by a gold wire 13 by wire bonding. At the same time, the subcarrier 4B with wiring and each wiring on the package 1 side are also connected by a gold wire by wire bonding.

  Finally, the second lens 9 and the pigtail fiber 11 are aligned using the experimental system shown in FIG. Specifically, a current of about 100 mA is supplied to any one channel of the DFB laser of the EADFB laser array 3C using the DC power source 22, and in this state, the power entering the optical power meter 25 is maximized. The second lens 9 and the pigtail fiber 11 are aligned, and the second lens 9, the ferrule collar 10, and the pigtail fiber 11 are fixed by welding with the YAG laser 23. The multi-channel optical transmission module is thus completed.

(4. Characteristics)
An experimental system for eye pattern measurement is shown in FIG. The configuration of this experimental system will be briefly described. The multi-channel optical transmission module 31 is connected to one end of the optical fiber 32, and the other end of the optical fiber 32 is connected to the optical demultiplexer 33. A photodetector 34 for detecting laser light from the multi-channel optical transmission module 31 is connected to the optical demultiplexer 33, and a DC power supply 39 and a pulse pattern generator 35 are connected to the multi-channel optical transmission module 31. Further, a sampling oscilloscope 36 is connected to the photodetector 34. Therefore, the laser light of the multi-channel optical transmission module 31 output based on the signal of the pulse pattern generator 35 is detected by the photodetector 34, and the detected laser light is analyzed by the sampling oscilloscope 36.

  Here, as a comparison, the conventional multi-channel optical transmission module shown in FIG. 14 was also measured at the same time. This conventional multi-channel optical transmission module has a configuration that does not use the above-described aerial high-frequency wiring board 18, and like the conventional multi-channel optical transmission module described with reference to FIG. Is provided.

  In both comparative measurements, the outside air was kept constant at 25 ° C., the bias current of the DFB laser unit was 100 mA, the bias voltage of the EA unit was −1.5 V, and the amplitude of the input signal was 2.0 Vpp. In this comparative measurement, for channel 2, the conventional multi-channel optical transmission module had an extinction ratio of 8.0 dB, whereas the multi-channel optical transmission module of this example had an extinction ratio of 8.9 dB. .

  In addition, when a bias current of 100 mA is applied to the DFB laser part, a bias voltage of -1.5 V is applied to the EA part, and an input signal amplitude of 2.0 Vpp is applied to the DFB laser part simultaneously, the channel 2 is a conventional multi-channel optical transmission module. Whereas the extinction ratio was 7.0 dB, the multichannel optical transmission module of the present example obtained an extinction ratio of 8.1 dB.

  An experimental system for measuring the bit error rate is shown in FIG. Next, BER characteristics were measured using this experimental system. The configuration of this experimental system will be briefly described. The multi-channel optical transmission module 31 is connected to one end of the optical fiber 32, and the other end of the optical fiber 32 is connected to the optical demultiplexer 33. A photodetector 34 for detecting laser light from the multi-channel optical transmission module 31 is connected to the optical demultiplexer 33, and a DC power supply 39 and a pulse pattern generator 35 are connected to the multi-channel optical transmission module 31. In addition, an error detector 37 is connected to the photodetector 34 via an optical variable attenuator 39. Therefore, the laser light of the multi-channel optical transmission module 31 output based on the signal of the pulse pattern generator 35 is detected by the photodetector 34, and the detected laser light is analyzed by the error detector 37.

  Here, both the conventional multi-channel optical transmission module and the multi-channel optical transmission module of the present embodiment were able to confirm error-free operation in each channel. In the simultaneous operation of four channels, the minimum light receiving sensitivity of channel 2 is -7 dB in the conventional multi-channel optical transmission module, whereas it is -8.4 dBm in the multi-channel optical transmission module of this embodiment. It was.

  From the above, it has been clarified that a multi-channel optical transmission module with little signal deterioration can be realized when a high-frequency signal exceeding 10 Gbps is handled.

(1. Configuration)
FIG. 16 is a block diagram showing the multi-channel optical transmission module of the present embodiment, FIG. 16 (a) is a top view thereof, and FIG. 16 (b) is a side view thereof. FIG. 17 is a top view of an aerial high-frequency wiring board described later. In the multi-channel optical transmission module of the present embodiment, the same reference numerals are given to the same components as those of the multi-channel optical transmission module described in the first embodiment.

  The multi-channel optical transmission module of the present embodiment includes a package 1 serving as a housing thereof, a Peltier element 6 provided in the package 1 for cooling an MZ integrated laser array 3D described later, and an upper surface of the Peltier element 6 Are provided on the upper surface of the LD carrier 2 on which the MZ integrated laser array 3D and a first lens 5A to be described later are disposed, and the MZ integrated laser array 3D is disposed on the upper surface of the LD carrier 2. A subcarrier 4B with wiring, a plurality of sets of semiconductor laser elements and modulators thereof are integrated, and an MZ integrated laser array 3D in which a multiplexer for multiplexing the optical paths therefrom is integrated, and an MZ integrated laser array And a first lens 5A that condenses the laser light from 3D. With such a configuration, the MZ integrated laser array 3D is mounted inside the package 1.

  Further, on the outside of one side surface of the package 1, the laser light collected by the first lens 5 </ b> A is collected, and a second lens 9 that enters the pigtail fiber 11 described later, and a ferrule collar that holds the pigtail fiber 11. 10 and a pigtail fiber 11 for propagating laser light from the MZ integrated laser array 3D to the outside.

  In this embodiment, a MCH-Zehnder modulator integrated DFB laser array with a two-channel multiplexer is used as the MZ integrated laser array 3D to be an array device for multi-channel optical transmission. Specifically, in the MZ integrated laser array 3D, a DFB laser is used as a semiconductor laser element (hereinafter referred to as a DFB laser unit), and a Mach-Zehnder modulator is used as a modulator (hereinafter referred to as an MZ unit). A multimode interference multiplexer (hereinafter referred to as an MMI multiplexer) is used as a multiplexer, and two sets of DFB laser units and MZ units are arranged on an InP substrate. In addition to being integrated, MMI multiplexers that combine optical paths from the MZ units are integrated. The multiplexer may be the arrayed waveguide grating multiplexer (AWG multiplexer) shown in the first embodiment.

In the MZ integrated laser array 3D, the channel spacing was 1000 μm, and the wavelength of each channel was 1550 nm and 1560 nm when the chip temperature was 25 ° C. Further, PRBS supplies a high-frequency signal of [2 ³¹ -1] to each channel with a data rate of 50 Gbps and NRZ.

  Further, on the side surface facing the inside of the package 1 sandwiching the MZ integrated laser array 3D, a high frequency signal is relayed between a wiring outside the package 1 and an aerial high frequency wiring board 19 (first high frequency wiring board) described later. A wiring board 16 is provided, and an aerial high-frequency wiring board 19 is fixed on the upper surface of the relay high-frequency wiring board 16 so as to bridge between the two relay high-frequency wiring boards 16. The relay high-frequency wiring board 16 is arranged such that the position of the upper surface thereof is higher than the position of the upper surface of the MZ integrated laser array 3D. As a result, the aerial high-frequency wiring board 19 is shown in FIG. As described above, when viewed from the MZ integrated laser array 3D, the laser beam is installed at an aerial position above the laser array 3D and crosses between the facing side surfaces inside the package 1.

  As shown in FIG. 17, the aerial high-frequency wiring board 19 has two channels (two pairs) of high-frequency wirings 19a for differential, and has a wiring shape of a differential coplanar line. In this embodiment, the material of the aerial high-frequency wiring board 19 itself is resin, the high-frequency wiring 19a, and the material of a ground wire 19b described later is Al.

  Each high-frequency wiring 19a can supply a high-frequency signal exceeding 10 Gbs, and is formed corresponding to the position on the plane of each MZ portion of the MZ integrated laser array 3D. Specifically, in the aerial high-frequency wiring board 19, a convex portion 19c is provided at the center of both side surfaces thereof, and the high-frequency wiring 19a is formed close to each MZ portion by forming the high-frequency wiring 19a up to the convex portion 19c. I am letting. Further, in order to make each high-frequency wiring 19a close to each electrode pad of each MZ portion, the interval between the high-frequency wirings 19a is wide in the convex portion 19c, but in order not to impair the high-frequency characteristics, the high-frequency wiring 19a. A ground line 19b is provided between them, and a portion of the convex portion 19c has a wiring shape of a GND coplanar line.

  In this embodiment, the relay high frequency wiring board 16 is also used to arrange the aerial high frequency wiring board 19, but at a position above the MZ integrated laser array 3D, between the facing side surfaces inside the package 1. Any structure may be used as long as the aerial high-frequency wiring board 19 can be disposed so as to cross. For example, the structure etc. which provide a support part like Example 1 may be sufficient.

  Since the aerial high-frequency wiring board 19 is installed at an aerial position above the MZ integrated laser array 3D, each high-frequency wiring 19a is formed to a position immediately above the MZ portion of each channel, that is, to the nearest position. Can do. In particular, in this embodiment, with the configuration shown in FIG. 17, each high-frequency wiring 19a is brought close to each electrode pad of each MZ portion. Therefore, when connecting the MZ portion of each channel and the high-frequency wiring 19a by wire bonding using the gold wire 13, it is possible to connect at the shortest possible distance. As a result, the length of the gold wire 13 can be suppressed to about 0.6 mm at all in all channels, and as described in FIG. 20 described above, when handling a high-frequency signal exceeding 10 Gbps, A good signal with little deterioration can be supplied to all channels. In addition, since the interval between the gold wires 13 is the interval between the channels, the interval can be increased as compared with the conventional case, and the occurrence of electrical crosstalk can be suppressed.

  In this embodiment, two sets of the DFB laser unit and the MZ unit are arranged in the laser array. However, as long as two or more sets of the DFB laser unit and the MZ unit are arranged in the laser array. By applying the present embodiment, the above effects can be achieved. That is, in the conventional connection structure, when two or more pairs of the DFB laser part and the MZ part are arranged in the laser array, that is, when there are four or more gold wires to the MZ part, This is because the length can be reduced by applying this embodiment.

(2. Principle of operation)
In the present embodiment, how to supply a high frequency signal to each channel of the MZ integrated laser array 3D will be described.

  The high-frequency signal that has entered the package 1 from the relay high-frequency wiring board 16 enters the aerial high-frequency wiring board 19 via the gold wire 13 and further passes through the gold wire 13 to each MZ portion of the MZ integrated laser array 3D. Supplied. A signal converted into light by the DFB laser unit of the MZ integrated laser array 3D and modulated by the MZ unit is combined into one waveguide through an MMI multiplexer and output. The output light is condensed by the first lens 5 </ b> A and the second lens 9 and coupled to the pigtail fiber 11.

(3. Assembly process)
The procedure for producing the multi-channel optical transmission module of this example is shown below.

  First, the MZ integrated laser array 3D and the termination resistor 14 are mounted on the subcarrier 4B with wiring. Next, after the subcarrier 4B with wiring is mounted on the LD carrier 2, the DFB laser part of the MZ integrated laser array 3D, the electrode pad of the MZ part of the subcarrier 4B with wiring and MZ integrated laser array 3D, and the termination resistor 14 are Each wire is connected by a gold wire 13 by wire bonding. In addition, the Peltier element 6 is mounted inside the package 1 and the relay high-frequency wiring board 16 is mounted on the opposite side surface inside the package 1 and higher than the upper surface of the MZ integrated laser array 3D.

  Then, the first lens 5A is aligned using the experimental system shown in FIG. Specifically, a current of about 100 mA is supplied to any one channel of the DFB laser unit of the MZ integrated laser array 3D using the DC power supply 22 and the DC probe 21. In this state, the CCD camera 24 is used to check the beam shape of the laser beam output from the MZ integrated laser array 3D so that the beam shape and position of the laser beam do not change at any position in the light traveling direction. The first lens 5 </ b> A is fixed to the LD carrier 2 by welding with the YAG laser 23.

  Thereafter, the LD carrier 2 is mounted on the Peltier element 6 mounted on the package 1. At this time, the aerial high-frequency wiring board 19 is temporarily mounted on the relay high-frequency wiring board 16, and the position of each electrode pad of each MZ portion of the MZ integrated laser array 3D matches the position of each high-frequency wiring 19a of the aerial high-frequency wiring board 19. Thus, the mounting position of the LD carrier 2 is adjusted. Next, the temporarily mounted aerial high-frequency wiring board 19 is fixed on the relay high-frequency wiring board 16. Then, the fixed aerial high-frequency wiring board 19, relay high-frequency wiring board 16, and MZ integrated laser array 3D are connected by a gold wire 13 by wire bonding.

  Finally, the second lens 9 and the pigtail fiber 11 are aligned using the experimental system shown in FIG. Specifically, the DC power supply 22 is used to supply a current of about 100 mA to an arbitrary channel of the DFB laser unit of the MZ integrated laser array 3D, and in this state, the power entering the optical power meter 25 is maximized. As described above, the second lens 9 and the pigtail fiber 11 are aligned, and the second lens 9, the ferrule collar 10, and the pigtail fiber 11 are fixed by welding with the YAG laser 23. The multi-channel optical transmission module is thus completed.

(4. Characteristics)
Using the eye pattern measurement experimental system shown in FIG. 13, the characteristics of the multi-channel optical transmission module were evaluated. Here, as a comparison, measurement of the conventional multi-channel optical transmission module shown in FIG. 19 was also performed at the same time. This conventional multi-channel optical transmission module does not use the above-mentioned aerial high-frequency wiring board 19 and has a structure in which a subcarrier 4B with wiring functioning as a high-frequency wiring board is provided on the LD carrier 2. In the MZ integrated laser array 3D, the upper side in the figure (see FIGS. 16 and 19) will be described as channel 1, and the lower side will be described as channel 2.

  In this comparative measurement, both were constant at 25 ° C., the bias current of the DFB laser part was 120 mA, the left electrode bias voltage of the MZ part was −3.5 V, the right electrode bias voltage was −2.5 V, Applied a differential signal and had an amplitude of 3.0 Vpp. In this comparative measurement, the channel 2 obtained an extinction ratio of 10.1 dB in the multichannel optical transmission module of this example, whereas the conventional multichannel optical transmission module had an extinction ratio of 9.5 dB. .

  When two channels are applied simultaneously, a bias current of 120 mA is applied to the DFB laser unit, a bias voltage of -0.5 V is applied to the MZ unit, and an input signal amplitude of 2.0 Vpp is applied. Whereas the extinction ratio was 8.9 dB, the multichannel optical transmission module of the present example obtained an extinction ratio of 9.8 dB.

  Next, BER characteristics were measured using the experimental system for bit error rate measurement shown in FIG. Here, both the conventional multi-channel optical transmission module and the multi-channel optical transmission module of the present embodiment were able to confirm error-free operation in each channel. In the simultaneous operation of two channels, the minimum light receiving sensitivity of channel 2 was −9 dBm for the conventional multi-channel optical transmission module, whereas it was −11 dBm for the multi-channel optical transmission module of this embodiment.

  From the above, it has been clarified that a multi-channel optical transmission module with little signal deterioration can be realized when a high-frequency signal exceeding 10 Gbps is handled.

  In the first to third embodiments described above, the aerial high-frequency wiring board has a wiring shape of a GND coplanar line, a microstrip line, and a differential coplanar line. Any wiring shape of the differential microstrip line may be used. In addition, the material of the aerial high-frequency wiring board is aluminum nitride, aluminum oxide, or resin, but any material of aluminum nitride, aluminum oxide, glass epoxy resin, or resin may be used. Moreover, although the materials of the high-frequency wiring and the ground wire are Au, Cu, and Al, any metal may be used as long as it is made of at least one element among Au, Cu, Pt, Ag, Al, Ti, and Ni. The same applies to the relay high-frequency wiring board.

  The semiconductor material for forming the DFB laser and EA may be a group III-V compound semiconductor composed of Si or at least two elements selected from Al, Ga, In, As, P, and Sb.

The material for forming the AWG multiplexer, the dielectric multiplexer, and the MMI multiplexer is SiO ₂ , Si, or at least two elements selected from Al, Ga, In, As, P, and Sb. Any III-V group compound semiconductor may be used.

  The present invention is suitable for a multi-channel optical transmission module that handles a high-frequency signal exceeding 10 Gbps.

1 Package (housing)
3B Laser array 3C EADFB laser array 3D MZ integrated laser array 13 Gold wire 16 Relay high frequency wiring board (second high frequency wiring board)
17 Aerial high-frequency wiring board (first high-frequency wiring board)
17a High-frequency wiring 18 Aerial high-frequency wiring board (first high-frequency wiring board)
18a High frequency wiring 19 Aerial high frequency wiring board (first high frequency wiring board)
19a High frequency wiring

Claims (12)

In a multi-channel optical transmission module in which a laser array in which a plurality of semiconductor laser elements are arranged is mounted inside a housing,
A first high-frequency wiring board having a plurality of high-frequency wirings for supplying a high-frequency signal;
The first high-frequency wiring board is disposed so as to cross between facing side surfaces in the housing at a position above the laser array, and
The high-frequency wiring is formed corresponding to the position on the plane of the plurality of semiconductor laser elements,
A multi-channel optical transmission module, wherein the high-frequency wiring and the semiconductor laser element are each connected by a gold wire. In a multi-channel optical transmission module in which a laser array in which a plurality of sets of semiconductor laser elements and modulators that modulate the semiconductor laser elements are arranged is mounted inside a housing,
A first high-frequency wiring board having a plurality of high-frequency wirings for supplying a high-frequency signal;
The first high-frequency wiring board is disposed so as to cross between facing side surfaces in the housing at a position above the laser array, and
The high-frequency wiring is formed corresponding to the position on the plane of the plurality of modulators,
A multi-channel optical transmission module, wherein the high-frequency wiring and the modulator are each connected by a gold wire. The multi-channel optical transmission module according to claim 1, wherein
A multi-channel optical transmission module, wherein the semiconductor laser element is a direct modulation DFB laser, and three or more direct modulation DFB lasers are arranged. The multi-channel optical transmission module according to claim 2,
A multi-channel characterized in that the semiconductor laser element is a DFB laser, the modulator is an electroabsorption optical modulator, and three or more sets of the DFB laser and the electroabsorption optical modulator are arranged. Optical transmission module. The multi-channel optical transmission module according to claim 2,
A multi-channel optical transmission module, wherein the semiconductor laser element is a DFB laser, the modulator is a Mach-Zehnder modulator, and two or more sets of the DFB laser and the Mach-Zehnder modulator are arranged. The multi-channel optical transmission module according to any one of claims 3 to 5,
The semiconductor laser element and the modulator are made of a III-V group compound semiconductor composed of Si or at least two kinds of elements of Al, Ga, In, As, P, and Sb. Multi-channel optical transmission module. The multi-channel optical transmission module according to any one of claims 1 to 6,
A multiplexer for multiplexing optical paths from the semiconductor element laser or the modulator is formed in the laser array, and the multiplexer is a multimode interference type multiplexer or an arrayed waveguide grating multiplexer. A multi-channel optical transmission module characterized by that. The multi-channel optical transmission module according to any one of claims 1 to 6,
A multiplexer for multiplexing optical paths from the semiconductor element laser or the modulator is provided independently of the laser array, and the multiplexer is a multiplexer using a dielectric filter. Multi-channel optical transmission module. The multi-channel optical transmission module according to claim 7 or 8,
The material of the multiplexer is a group III-V compound semiconductor composed of at least two kinds of elements of SiO ₂ , Si, or Al, Ga, In, As, P, and Sb. Multi-channel optical transmission module. The multi-channel optical transmission module according to any one of claims 1 to 9,
A second high-frequency wiring board that relays between the external wiring and the first high-frequency wiring board is provided on each side surface facing the inside of the housing, and the top surfaces of the two second high-frequency wiring boards are high. The multi-channel optical transmission module, wherein the first high-frequency wiring board is fixed to the upper surfaces of the two second high-frequency wiring boards, with the height higher than the height of the upper surface of the laser array. The multi-channel optical transmission module according to any one of claims 1 to 10,
A multi-channel optical transmission module characterized in that a material of the first high-frequency wiring board and the second high-frequency wiring board is any one of aluminum oxide, aluminum nitride, glass epoxy resin, and resin. The multi-channel optical transmission module according to any one of claims 1 to 11,
The wiring shape of the first high frequency wiring board and the second high frequency wiring board is any one of a GND coplanar line, a microstrip line, a differential coplanar line, and a differential microstrip line. The multi-channel characterized in that the material of wiring of the first high-frequency wiring board and the second high-frequency wiring board is a metal composed of at least one element of Au, Pt, Ag, Al, Ti, Ni, and Cu. Optical transmission module.

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