WO2022097289A1 - Iq optical modulator - Google Patents

Iq optical modulator Download PDF

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Publication number
WO2022097289A1
WO2022097289A1 PCT/JP2020/041612 JP2020041612W WO2022097289A1 WO 2022097289 A1 WO2022097289 A1 WO 2022097289A1 JP 2020041612 W JP2020041612 W JP 2020041612W WO 2022097289 A1 WO2022097289 A1 WO 2022097289A1
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optical
modulator
light
optical modulator
input
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PCT/JP2020/041612
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French (fr)
Japanese (ja)
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泰彰 橋詰
義弘 小木曽
常祐 尾崎
光映 石川
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日本電信電話株式会社
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Priority to PCT/JP2020/041612 priority Critical patent/WO2022097289A1/en
Publication of WO2022097289A1 publication Critical patent/WO2022097289A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 

Definitions

  • the present invention relates to an IQ optical modulator capable of operating at high speed and in a wide wavelength band.
  • multi-valued light modulators using digital coherent technology play a major role in realizing large-capacity transceivers exceeding 100 Gbps.
  • the multi-valued light modulator is capable of zero-charp drive, which is composed of a Mach-Zender interference type optical waveguide (MZ optical waveguide) that splits the optical input into two arms, combines them after phase shift, and outputs interference.
  • Optical modulators (MZM) are built in parallel and multi-stage. With such a configuration, independent signals can be added to the amplitude and phase of light.
  • a typical polarization-multiplexed IQ optical modulator which is currently becoming widespread in communication networks, has a so-called nested structure in which each arm of the parent MZM is composed of child MZMs.
  • Two child MZMs are provided in parallel corresponding to each of the X and Y polarization channels, and an MZM (Quad-pallell MZM) having a total of four child MZMs is configured.
  • the two arms of each child MZM are provided with a traveling wave type electrode to which an RF modulated electric signal for performing a modulation operation is input to the optical signal propagating in the optical waveguide.
  • one of the two such paired child MZMs is the I channel and the other is the Q channel.
  • an RF-modulated electric signal is input to one end of a modulation electrode provided along the arm optical waveguide of the child MZM to generate an electro-optical effect, and the optical waveguide of the child MZM is generated.
  • Phase modulation is applied to the two optical signals propagating within (Patent Document 1).
  • FIG. 1 shows an example of a conventional polarization multiplex IQ optical modulator.
  • MZM101X for an X polarization channel and MZM101Y for a Y polarization channel are formed on a semiconductor chip, and MZM101XI and 101YI for the I channel and MZM101YI for the Q channel, respectively. It has a nested structure including MZM101XQ and 101YQ.
  • the input optical waveguide 102 formed from the center of one side of the semiconductor chip passes between MZM101X and 101Y and is connected to the light demultiplexer 103.
  • the light demultiplexers 104X and 104Y are connected to the output of the light demultiplexer 103, and MZM101XI, 101XQ and MZM101YI, 101YQ are connected to the output, respectively.
  • the MZM101X for the X polarization channel is provided with the MZM101XI and the phase adjuster 106XI for the I channel and the MZM101XQ and the phase adjuster 106XQ for the Q channel between the light demultiplexer 104X and the optical combiner 105X. ing. Further, in the MZM101XI for the I channel, an MZ optical waveguide 109XIa, 109XIb and a phase adjuster 110XIa, 110XIb are provided between the optical demultiplexer 107XI and the optical combiner 108XI.
  • the traveling wave electrode formed on the MZ optical waveguide 109XIa, 109XIb is connected to the RF signal line 111XIa, 111XIb formed from the other side of the semiconductor chip, and the RF modulation signal is supplied. Since the configuration for the Q channel is the same, the description thereof will be omitted. Further, since the MZM101Y for the Y polarization channel has the same structure as the MZM101X for the X polarization channel, the description thereof will be omitted.
  • the input light 121 is branched by the optical demultiplexer 103 via the input optical waveguide 102, and each channel light of X and Y polarization is photomodulated by an RF modulation signal in MZM101X and MZM101Y, and one side of the semiconductor chip. Is output as modulated output light 122X, 122Y.
  • the waveguide structure is symmetric between the IQ channels, so that the characteristic error between the channels is small with respect to the temperature fluctuation and temperature distribution in the chip.
  • the line length L1 of the RF signal lines 111XIa and 111XIb for inputting the RF modulated signal becomes long, there is a concern that the high frequency characteristics may be deteriorated.
  • FIG. 2 shows another example of a conventional polarization-multiplexed IQ optical modulator.
  • MZM201X for an X polarization channel and MZM201Y for a Y polarization channel are formed on a semiconductor chip, and MZM201XI and 201YI for the I channel and MZM201YI for the Q channel are formed, respectively. It has a nested structure including MZM201XQ and 201YQ.
  • the input optical waveguide 202 formed from the center of one side of the semiconductor chip passes between MZM201X and 201Y and is connected to the light demultiplexer 203.
  • the optical demultiplexers 204X and 204Y are connected to the output of the light demultiplexer 203, and the optical waveguide on the output side thereof is folded back 180 ° and connected to each of the MZM201XI and 201XQ and the MZM201YI and 201YQ.
  • MZM201X and MZM201Y are the same as that of MZM101X and MZM101Y except for the folded structure, so the description thereof will be omitted.
  • the input light 221 is branched by the optical demultiplexer 203 via the input optical waveguide 202, and each channel light of X and Y polarization is photomodulated by an RF modulation signal in MZM201X and MZM201Y, and one side of the semiconductor chip. Is output as modulated output light 222X, 222Y.
  • the line length L2 of the RF signal lines 211XIa and 211XIb for inputting the RF modulation signal can be shortened, and deterioration of high frequency characteristics can be suppressed.
  • the waveguide structure between the IQ channels in the MZM201X and the MZM201Y becomes asymmetric, the characteristic error between the IQ channels becomes large with respect to the temperature fluctuation / temperature distribution in the semiconductor chip.
  • the phase adjuster in the above-mentioned example is a phase adjuster utilizing a thermo-optical effect, and heats an optical waveguide by energizing a metal material (heater) loaded above the optical waveguide and propagates in the optical waveguide.
  • the phase of the optical signal is changed.
  • the electric power (P ⁇ ) required to change the phase by ⁇ is required to be about 30 mW, and further reduction in power consumption is required for miniaturization.
  • An object of the present invention is to provide an IQ optical modulator capable of suppressing deterioration of high frequency characteristics, improving resistance to temperature fluctuations and temperature distribution, and achieving miniaturization and low power consumption.
  • the present invention is an IQ optical modulator having a first optical modulator for an I channel and a second optical modulator for a Q channel, wherein the present invention is a semiconductor.
  • a second optical waveguide connected to an input optical waveguide formed from one side of the chip, provided between the first and second light modulators, and demultiplexing the input light to the first and second light modulators.
  • a first optical modulator that combines the output light from the first and second light modulators and outputs the light from one side of the semiconductor chip, and the first optical modulator. It is a first phase adjuster inserted between the output of the above and the first optical modulator, and is an optical waveguide from the first optical demultiplexer to the first optical modulator and the first optical modulator.
  • the optical waveguide from the first light modulator to the first optical modulator was inserted between the first phase adjuster in which the optical waveguide was arranged below the same electrode, the output of the second light modulator, and the first optical modulator.
  • FIG. 1 It is a figure which shows an example of the conventional IQ optical modulator of a polarization multiplex type. It is a figure which shows the other example of the conventional polarization multiplex type IQ light modulator. It is a figure which shows the IQ light modulator which concerns on Example 1 of this invention. It is sectional drawing which shows the structure of the phase adjuster of the IQ light modulator which concerns on Example 1.
  • FIG. It is a figure which shows the IQ light modulator which concerns on Example 2 of this invention.
  • FIG. 3 shows the IQ optical modulator according to the first embodiment of the present invention.
  • the IQ optical modulator 300 is a single-polarized IQ optical modulator, which comprises an I-channel optical modulator (MZM) 301I and a Q-channel optical modulator (MZM) 301Q on a semiconductor chip. It has a nested structure.
  • the input optical waveguide 302 formed from one side of the semiconductor chip is connected to the optical demultiplexer 304 (first optical demultiplexer) provided between the MZM 301I and 301Q via the optical cross waveguide 312. ..
  • the IQ optical modulator 300 is provided with an MZM301I and a phase adjuster 306I for the I channel and an MZM301Q and the phase adjuster 306Q for the Q channel between the light demultiplexer 304 and the optical duplexer 305. .. Further, the MZM301I for the I channel is provided with a Mach-Zehnder interference type arm waveguide (MZ optical waveguide) 309Ia, 309Ib and a phase adjuster 310Ia, 310Ib between the optical demultiplexer 307I and the optical combiner 308I. Has been done.
  • MZ optical waveguide Mach-Zehnder interference type arm waveguide
  • the traveling wave electrode formed on the MZ optical waveguides 309Ia and 309Ib is connected to the RF signal lines 311Ia and 311Ib formed from the other side of the semiconductor chip, and the RF modulation signal is supplied. Since the configuration for the Q channel is the same, the description thereof will be omitted.
  • the input light 321 is photomodulated by an RF modulation signal in MZM301I and MZM301Q via an input optical waveguide 302, is coupled by an optical combiner 305 (first optical combiner), and is modulated and output from one side of a semiconductor chip. It is output as light 322.
  • the waveguide structure is symmetric between IQ channels, the characteristic error between channels is small with respect to the temperature fluctuation and temperature distribution in the chip.
  • the phase adjuster 306I has two parallel optical waveguides, that is, an optical waveguide on the input side from the optical waveguide 304 to the optical waveguide 307I, and an output side from the optical waveguide 308I to the optical waveguide 305.
  • the optical waveguide of the above is arranged under the same electrode. Since the heating area of the same heater is reciprocated twice, the length of the heater can be halved as compared with the conventional one, and the heater can be shortened without deteriorating the reliability of the heater. , It can also contribute to the miniaturization of the IQ optical modulator.
  • the optical waveguide 312 is composed of two 1 ⁇ 1 MMI couplers in which the intersections of the two optical waveguides are arranged in a cross shape in which the light propagation directions are orthogonal to each other.
  • the two 1 ⁇ 1 MMI couplers have a cross-shaped planar shape and are formed of the same core-clad structure, and have a structure in which two lights having orthogonal propagation directions intersect in the same plane.
  • a 1x1 MMI coupler many modes propagate independently, but each mode has a different propagation velocity, so at a certain propagation length, the light is focused as a result of the interference of those modes. Have. By setting the center of the intersection of the two MMI couplers as this condensing point, it can function as a low-loss optical cross-guided path.
  • FIG. 4 shows the structure of the phase adjuster of the IQ optical modulator according to the first embodiment.
  • FIG. 3 is a cross-sectional view taken along the line IV-IV'shown in FIG.
  • the n-InP layer 402, the lower semiconductor clad layer 403, the semiconductor core layer 404, and the upper semiconductor clad layer 405 are laminated in this order on the SI-InP layer 401, which is a substrate.
  • a desired mesa structure is formed from the lower semiconductor clad layer 403 to the upper semiconductor clad layer 405 by dry etching, and functions as two optical waveguides.
  • the two optical waveguides are covered with an organic material 406 and flattened, and a metal electrode serving as a heater 407 is formed on the organic material 406.
  • the width of the optical waveguide is 2 ⁇ m, the distance between the centers of the optical waveguide is 4 ⁇ m, and the width of the heater is 10 ⁇ m, so that two optical waveguides can be heated by the same heater. Since light propagates in the heated region, a phase change is applied to the optical waveguide. Therefore, by propagating twice in the same heated region, it is possible to obtain twice the phase change as compared with the conventional single propagation. can.
  • the electric power (P ⁇ ) required to change the phase by ⁇ is 30 mW, but in the first embodiment, it can be reduced to about half.
  • FIG. 5 shows the IQ optical modulator according to the second embodiment of the present invention.
  • the IQ optical modulator 500 is a single-polarized IQ optical modulator, which has a nested structure of MZM501I for I-channel and MZM501Q for Q-channel on a semiconductor chip.
  • the input optical waveguide 502 formed from one side of the semiconductor chip is connected to the optical demultiplexer 504 (first optical demultiplexer) provided between the MZM501I and 501Q via the optical cross waveguide 512. ..
  • the IQ optical modulator 500 is provided with an MZM501I and a phase adjuster 506I for an I channel and an MZM501Q and a phase adjuster 506Q for a Q channel between the light demultiplexer 504 and the optical combiner 505. .
  • the MZM501I for the I channel is provided with an optical demultiplexer 507I (second optical demultiplexer) and phase adjusters 510Ia and 510Ib between the MZM501I and 501Q, and the optical waveguide on the output side is folded back by 180 °. It is connected to the Mach-Zehnder interference type arm waveguide (MZ optical waveguide) 509Ia, 509Ib.
  • MZ optical waveguide Mach-Zehnder interference type arm waveguide
  • the light propagation direction of the light demultiplexer 507I and the light propagation direction of the MZ optical waveguides 509Ia and 509Ib are opposite to each other.
  • the optical waveguide inside the folded portion is provided with a bent portion so that the lengths of the optical waveguides from the phase adjusters 510Ia and 510Ib to the MZ optical waveguides 509Ia and 509Ib are equal.
  • the outputs of the MZ optical waveguides 509Ia and 509Ib are combined by the optical combiner 508I and input to the phase adjuster 506I.
  • the traveling wave electrode formed on the MZ optical waveguide 509Ia, 509Ib is connected to the RF signal line 511Ia, 511Ib formed from the other side of the semiconductor chip, and the RF modulation signal is supplied. Since the configuration for the Q channel is the same, the description thereof will be omitted.
  • the input light 521 is photomodulated by the RF modulation signal in the MZM501I and MZM501Q via the input optical waveguide 502, combined by the optical combiner 505 (first optical combiner), and modulated and output from one side of the semiconductor chip. It is output as light 522.
  • the phase adjusters 510Ia and 510Ib are provided between the MZM501I and 501Q, the line lengths of the RF signal lines 511Ia and 511Ib can be shortened as compared with the first embodiment, and the semiconductor chip can be shortened. Can also be shortened.
  • the phase adjuster 506I has two parallel optical waveguides, that is, an optical waveguide on the input side from the optical waveguide 504 to the optical waveguide 507I, and an output side from the optical waveguide 508I to the optical waveguide 505.
  • the optical waveguide of the above is arranged under the same electrode. Since the heating area of the same heater is reciprocated twice, the length of the heater can be halved as compared with the conventional one, and the heater can be shortened without deteriorating the reliability of the heater. , It can also contribute to the miniaturization of the IQ optical modulator.
  • FIG. 6 shows a polarization-multiplexed IQ optical modulator according to the third embodiment of the present invention.
  • the polarization multiplexing type IQ optical modulator 600 two IQ optical modulators 500 of Example 2 shown in FIG. 5 are integrated in parallel on a semiconductor chip, one for the X polarization channel and the other for the Y polarization channel. It has a nested structure.
  • the input optical waveguide 602 formed from the center of one side of the semiconductor chip is connected to the light demultiplexer 603, and its output is input to the MZM601X for the X polarization channel and the MZM601Y for the Y polarization channel.
  • optical demultiplexers 604X and 604Y are connected to the output of the optical demultiplexer 603 via optical cross-guide paths 612X and 612Y, and MZM601XI, 601XQ and MZM601YI, 601YQ are connected to the outputs, respectively. To.
  • the MZM601X for the X polarization channel is provided with the MZM601XI and the phase adjuster 606XI for the I channel and the MZM601XQ and the phase adjuster 606XQ for the Q channel between the light demultiplexer 604X and the optical combiner 605X. ing. Further, the MZM601XI for the I channel is provided with an optical demultiplexer 607XI and a phase adjuster 610XIa, 610XIb between the MZM601XI and 601XIb, and the optical waveguide on the output side thereof is folded back 180 ° to form the MZ optical waveguide 609XIa, 609XIb. Is connected to.
  • the optical waveguide inside the folded portion is provided with a bent portion so that the lengths of the optical waveguides from the phase adjusters 610XIa and 610XIb to the MZ optical waveguide 609XIa and 609XIb are equal.
  • the outputs of the MZ optical waveguides 609XIa and 609XIb are combined by the optical combiner 608XI and input to the phase adjuster 606XI.
  • the outputs of the phase adjusters 606XI and 606XQ are combined by the optical combiner 605X and output as the modulated output light 622X.
  • the traveling wave electrode formed on the MZ optical waveguide 609XIa, 609XIb is connected to the RF signal line 611XIa, 611XIb formed from the other side of the semiconductor chip, and the RF modulation signal is supplied. Since the configuration for the Q channel is the same, the description thereof will be omitted. Further, since the MZM601Y for the Y polarization channel has the same structure as the MZM601X for the X polarization channel, the description thereof will be omitted.
  • the input light 621 is branched by the optical demultiplexer 603 via the input optical waveguide 602, and each channel light of X and Y polarization is photomodulated by an RF modulation signal in MZM601X and MZM601Y, and one side of the semiconductor chip. Is output as modulated output light 622X, 622Y.
  • phase adjusters 610XIa and 610XIb are provided between the MZM601XI and 601XQ, the line length of the RF signal lines 611XIa and 611XIb can be shortened and the semiconductor chip can be shortened. can.
  • phase adjusters 606XI and 606XQ have two parallel optical waveguides, that is, an optical waveguide on the input side from the optical demultiplexer 604X to the optical demultiplexer 607XI and 607XQ, and the optical waveguide from the optical combiner 608XI and 608XQ.
  • the output-side optical waveguide leading to the device 605X is located below the same electrode. Since the heating area of the same heater is reciprocated twice, the length of the heater can be halved as compared with the conventional one, and the heater can be shortened without deteriorating the reliability of the heater. , It can also contribute to the miniaturization of the IQ optical modulator.
  • FIG. 7 shows a polarization-multiplexed IQ optical modulator according to the fourth embodiment of the present invention.
  • the polarization multiplexing type IQ optical modulator 700 two IQ optical modulators 500 of Example 2 shown in FIG. 5 are integrated in parallel on a semiconductor chip, one for the X polarization channel and the other for the Y polarization channel. It has a nested structure.
  • the input optical waveguide 702 formed from the center of one side of the semiconductor chip is connected to the light demultiplexer 703, and its output is input to the MZM701X for the X polarization channel and the MZM701Y for the Y polarization channel.
  • An optical demultiplexer 704X, 704Y is connected to the output of the optical demultiplexer 703 via an optical cross-guided waveguide 712X, 712Y, and further, MZM701XI, 701XQ and MZM701YI, 701YQ are connected to the output, respectively.
  • the output of the MZM701XI, 701XQ is combined by the optical combiner 705X via the phase adjuster 706XI, 706XQ, and is output as the modulated output light 722X. Since the configurations of the MZM701XI and 701XQ are the same as those of the MZM601YI and 601YQ of the third embodiment shown in FIG. 6, the description thereof will be omitted.
  • the difference from the third embodiment is that a dummy optical cross-guided waveguide 713X is inserted between the phase adjuster 706XI and the optical combiner 705X. According to this configuration, since the number of intersections of the optical waveguide is equal between the XY channel and the IQ channel, it is possible to suppress the characteristic difference between the channels of the optical characteristics.
  • FIG. 8 shows a polarization-multiplexed IQ optical modulator according to the fifth embodiment of the present invention.
  • the polarization multiplex IQ optical modulator 800 is the MZM801X for the X polarization channel and the MZM801Y for the Y polarization channel on the semiconductor chip, and the MZM601X for the X polarization channel and the MZM601X for the X polarization channel shown in FIG. It has a nested structure including MZM601Y for the Y polarization channel, or MZM701X for the X polarization channel of Example 4 shown in FIG. 7 and MZM701Y for the Y polarization channel.
  • the difference between the third embodiment and the fourth embodiment is that a variable branch circuit is provided in the input section.
  • the variable branch circuit has a configuration in which a 1-input 2-output optical demultiplexer 831, a DC phase adjuster 832a, 832b, and a 2-input 2-output optical combine demultiplexer 833 are connected in order to the input optical waveguide 802. ing.
  • the specification of the difference in optical insertion loss between X-polarized and Y-polarized channels is determined as PDL (polarization dependent loss).
  • PDL polarization dependent loss
  • VOA variable optical attenuator
  • the optical intensity of the channel having the larger optical power intensity is attenuated and adjusted, so that excessive optical loss occurs in principle.
  • variable branch circuit of the fifth embodiment functions as an optical power trimming mechanism capable of arbitrarily adjusting the branch ratio. As a result, PDL compensation can be performed while maintaining the light intensity without excessive loss.

Abstract

The present invention provides an IQ optical modulator capable of suppressing the deterioration of high frequency characteristic, improving resistance to temperature fluctuation and temperature distribution, and achieving reductions in size and power consumption.　An embodiment relates to an IQ optical modulator (300) having a first optical modulator (301I) for an I channel and a second optical modulator (301Q) for a Q channel, and provided with: a first optical demultiplexer (304) that is connected to an input optical waveguide (302) formed from one side of a semiconductor chip, is provided between the first and second optical modulators, and demultiplexes input light into the first and second optical modulators; a first optical multiplexer (305) that multiplexes output light from the first and second optical modulators, and outputs the multiplexed output light from the one side of the semiconductor chip; and first and second phase regulators (306I, 306Q) that are inserted between the output of the first optical modulator and the first optical multiplexer. In each of the phase regulators, an optical waveguide from the first optical demultiplexer to the first or the second optical modulator and an optical waveguide from the first or the second optical modulator to the first optical multiplexer are disposed in the lower part of the same electrode.

Description

ＩＱ光変調器IQ light modulator
　本発明は、高速かつ広波長帯域動作可能なＩＱ光変調器に関する。 The present invention relates to an IQ optical modulator capable of operating at high speed and in a wide wavelength band.
　光通信システムの大容量化に伴い、高度な光変調方式に対応した高速光変調器が求められている。特にデジタルコヒーレント技術を用いた多値光変調器は、１００Ｇｂｐｓを超える大容量トランシーバ実現に大きな役割を果たしている。多値光変調器は、光入力を２つのアームに分波し、移相後に合波して干渉出力するマッハ・ツェンダー干渉型の光導波路（ＭＺ光導波路）で構成された、ゼロチャープ駆動が可能な光変調器（ＭＺＭ）が並列多段に内蔵されている。このような構成により、光の振幅及び位相に、それぞれ独立の信号を付加させることができる。 With the increase in capacity of optical communication systems, there is a demand for high-speed optical modulators that support advanced optical modulation methods. In particular, multi-valued light modulators using digital coherent technology play a major role in realizing large-capacity transceivers exceeding 100 Gbps. The multi-valued light modulator is capable of zero-charp drive, which is composed of a Mach-Zender interference type optical waveguide (MZ optical waveguide) that splits the optical input into two arms, combines them after phase shift, and outputs interference. Optical modulators (MZM) are built in parallel and multi-stage. With such a configuration, independent signals can be added to the amplitude and phase of light.
　現在、通信網への普及が進んでいる代表的な偏波多重型のＩＱ光変調器は、親ＭＺＭの各アームのそれぞれが子ＭＺＭで構成された、いわゆる入れ子構造を有する。Ｘ、Ｙの偏波チャネルのそれぞれに対応して子ＭＺＭが２つ並列に設けられ、計４つの子ＭＺＭを有するＭＺＭ（Ｑｕａｄ－ｐａｒａｌｌｅｌ　ＭＺＭ）が構成される。各々の子ＭＺＭの２つのアームには、光導波路内を伝搬する光信号に変調動作を行うためのＲＦ変調電気信号が入力される進行波型電極が設けられている。各偏波チャネルにおいて、このような対をなす２つの子ＭＺＭの一方がＩチャネル、他方がＱチャネルにあたる。 A typical polarization-multiplexed IQ optical modulator, which is currently becoming widespread in communication networks, has a so-called nested structure in which each arm of the parent MZM is composed of child MZMs. Two child MZMs are provided in parallel corresponding to each of the X and Y polarization channels, and an MZM (Quad-pallell MZM) having a total of four child MZMs is configured. The two arms of each child MZM are provided with a traveling wave type electrode to which an RF modulated electric signal for performing a modulation operation is input to the optical signal propagating in the optical waveguide. In each polarization channel, one of the two such paired child MZMs is the I channel and the other is the Q channel.
　かかる偏波多重型のＩＱ光変調器は、子ＭＺＭのアーム光導波路に沿って設けられた変調電極の一端にＲＦ変調電気信号を入力することにより、電気光学効果を生じさせて子ＭＺＭの光導波路内を伝搬する２つの光信号に位相変調を施している（特許文献１）。 In such a polarization-multiplexed IQ optical modulator, an RF-modulated electric signal is input to one end of a modulation electrode provided along the arm optical waveguide of the child MZM to generate an electro-optical effect, and the optical waveguide of the child MZM is generated. Phase modulation is applied to the two optical signals propagating within (Patent Document 1).
　図１に、従来の偏波多重型のＩＱ光変調器の一例を示す。偏波多重型のＩＱ光変調器１００は、半導体チップ上に、Ｘ偏波チャネル用のＭＺＭ１０１ＸとＹ偏波チャネル用のＭＺＭ１０１Ｙとが形成され、それぞれにＩチャネル用のＭＺＭ１０１ＸＩ，１０１ＹＩとＱチャネル用のＭＺＭ１０１ＸＱ，１０１ＹＱとを含む入れ子構造を有する。半導体チップの一方の辺の中央から形成された入力光導波路１０２は、ＭＺＭ１０１Ｘ、１０１Ｙの間を通り、光分波器１０３に接続される。光分波器１０３の出力に、光分波器１０４Ｘ，１０４Ｙが接続され、さらに、その出力にはＭＺＭ１０１ＸＩ，１０１ＸＱとＭＺＭ１０１ＹＩ，１０１ＹＱのそれぞれが接続される。 FIG. 1 shows an example of a conventional polarization multiplex IQ optical modulator. In the polarization multiplex IQ optical modulator 100, MZM101X for an X polarization channel and MZM101Y for a Y polarization channel are formed on a semiconductor chip, and MZM101XI and 101YI for the I channel and MZM101YI for the Q channel, respectively. It has a nested structure including MZM101XQ and 101YQ. The input optical waveguide 102 formed from the center of one side of the semiconductor chip passes between MZM101X and 101Y and is connected to the light demultiplexer 103. The light demultiplexers 104X and 104Y are connected to the output of the light demultiplexer 103, and MZM101XI, 101XQ and MZM101YI, 101YQ are connected to the output, respectively.
　Ｘ偏波チャネル用のＭＺＭ１０１Ｘは、光分波器１０４Ｘと光合波器１０５Ｘとの間に、Ｉチャネル用のＭＺＭ１０１ＸＩおよび位相調整器１０６ＸＩと、Ｑチャネル用のＭＺＭ１０１ＸＱおよび位相調整器１０６ＸＱとが設けられている。さらに、Ｉチャネル用のＭＺＭ１０１ＸＩは、光分波器１０７ＸＩと光合波器１０８ＸＩとの間に、ＭＺ光導波路１０９ＸＩａ，１０９ＸＩｂおよび位相調整器１１０ＸＩａ，１１０ＸＩｂが設けられている。ＭＺ光導波路１０９ＸＩａ，１０９ＸＩｂに形成された進行波電極は、半導体チップの他方の辺から形成されたＲＦ信号線１１１ＸＩａ，１１１ＸＩｂに接続され、ＲＦ変調信号が供給される。Ｑチャネル用の構成も同じであるので説明は省略する。また、Ｙ偏波チャネル用のＭＺＭ１０１ＹもＸ偏波チャネル用のＭＺＭ１０１Ｘと同じ構造を有するので説明は省略する。 The MZM101X for the X polarization channel is provided with the MZM101XI and the phase adjuster 106XI for the I channel and the MZM101XQ and the phase adjuster 106XQ for the Q channel between the light demultiplexer 104X and the optical combiner 105X. ing. Further, in the MZM101XI for the I channel, an MZ optical waveguide 109XIa, 109XIb and a phase adjuster 110XIa, 110XIb are provided between the optical demultiplexer 107XI and the optical combiner 108XI. The traveling wave electrode formed on the MZ optical waveguide 109XIa, 109XIb is connected to the RF signal line 111XIa, 111XIb formed from the other side of the semiconductor chip, and the RF modulation signal is supplied. Since the configuration for the Q channel is the same, the description thereof will be omitted. Further, since the MZM101Y for the Y polarization channel has the same structure as the MZM101X for the X polarization channel, the description thereof will be omitted.
　入力光１２１は、入力光導波路１０２を経て光分波器１０３で分岐され、Ｘ，Ｙ偏波の各チャネル光は、ＭＺＭ１０１ＸとＭＺＭ１０１Ｙにおいて、ＲＦ変調信号によって光変調され、半導体チップの一方の辺から変調出力光１２２Ｘ、１２２Ｙとして出力される。 The input light 121 is branched by the optical demultiplexer 103 via the input optical waveguide 102, and each channel light of X and Y polarization is photomodulated by an RF modulation signal in MZM101X and MZM101Y, and one side of the semiconductor chip. Is output as modulated output light 122X, 122Y.
　この構成によれば、ＭＺＭ１０１Ｘ、１０１Ｙのそれぞれにおいて、ＩＱチャネル間で導波路構造が対称であるため、チップ内の温度変動・温度分布に対してチャネル間の特性誤差は小さい。一方、ＲＦ変調信号を入力するＲＦ信号線１１１ＸＩａ，１１１ＸＩｂの線路長Ｌ１が長くなるため、高周波特性の劣化が懸念される。 According to this configuration, in each of the MZM101X and 101Y, the waveguide structure is symmetric between the IQ channels, so that the characteristic error between the channels is small with respect to the temperature fluctuation and temperature distribution in the chip. On the other hand, since the line length L1 of the RF signal lines 111XIa and 111XIb for inputting the RF modulated signal becomes long, there is a concern that the high frequency characteristics may be deteriorated.
　図２に、従来の偏波多重型のＩＱ光変調器の他の例を示す。偏波多重型のＩＱ光変調器２００は、半導体チップ上に、Ｘ偏波チャネル用のＭＺＭ２０１ＸとＹ偏波チャネル用のＭＺＭ２０１Ｙとが形成され、それぞれにＩチャネル用のＭＺＭ２０１ＸＩ，２０１ＹＩとＱチャネル用のＭＺＭ２０１ＸＱ，２０１ＹＱとを含む入れ子構造を有する。半導体チップの一方の辺の中央から形成された入力光導波路２０２は、ＭＺＭ２０１Ｘ、２０１Ｙの間を通り、光分波器２０３に接続される。光分波器２０３の出力に、光分波器２０４Ｘ，２０４Ｙが接続され、さらに、その出力側の光導波路を１８０°折り返して、ＭＺＭ２０１ＸＩ，２０１ＸＱとＭＺＭ２０１ＹＩ，２０１ＹＱのそれぞれに接続している。 FIG. 2 shows another example of a conventional polarization-multiplexed IQ optical modulator. In the polarization multiplex IQ optical modulator 200, MZM201X for an X polarization channel and MZM201Y for a Y polarization channel are formed on a semiconductor chip, and MZM201XI and 201YI for the I channel and MZM201YI for the Q channel are formed, respectively. It has a nested structure including MZM201XQ and 201YQ. The input optical waveguide 202 formed from the center of one side of the semiconductor chip passes between MZM201X and 201Y and is connected to the light demultiplexer 203. The optical demultiplexers 204X and 204Y are connected to the output of the light demultiplexer 203, and the optical waveguide on the output side thereof is folded back 180 ° and connected to each of the MZM201XI and 201XQ and the MZM201YI and 201YQ.
　ＭＺＭ２０１ＸとＭＺＭ２０１Ｙの構成は、折り返し構造を除いて、ＭＺＭ１０１ＸとＭＺＭ１０１Ｙと同じなので説明は省略する。 The configuration of MZM201X and MZM201Y is the same as that of MZM101X and MZM101Y except for the folded structure, so the description thereof will be omitted.
　入力光２２１は、入力光導波路２０２を経て光分波器２０３で分岐され、Ｘ，Ｙ偏波の各チャネル光は、ＭＺＭ２０１ＸとＭＺＭ２０１Ｙにおいて、ＲＦ変調信号によって光変調され、半導体チップの一方の辺から変調出力光２２２Ｘ、２２２Ｙとして出力される。 The input light 221 is branched by the optical demultiplexer 203 via the input optical waveguide 202, and each channel light of X and Y polarization is photomodulated by an RF modulation signal in MZM201X and MZM201Y, and one side of the semiconductor chip. Is output as modulated output light 222X, 222Y.
　この構成によれば、ＲＦ変調信号を入力するＲＦ信号線２１１ＸＩａ，２１１ＸＩｂの線路長Ｌ２を短尺化することができ、高周波特性の劣化を抑制することができる。一方、ＭＺＭ２０１ＸとＭＺＭ２０１ＹとにおけるＩＱチャネル間の導波路構造が非対称性になるので、半導体チップ内の温度変動・温度分布に対して、ＩＱチャネル間の特性誤差が大きくなってしまう。 According to this configuration, the line length L2 of the RF signal lines 211XIa and 211XIb for inputting the RF modulation signal can be shortened, and deterioration of high frequency characteristics can be suppressed. On the other hand, since the waveguide structure between the IQ channels in the MZM201X and the MZM201Y becomes asymmetric, the characteristic error between the IQ channels becomes large with respect to the temperature fluctuation / temperature distribution in the semiconductor chip.
　上述した例における位相調整器は、熱光学効果を利用した位相調整器であり、光導波路の上方に装荷された金属材料（ヒータ）に通電することにより光導波路を加熱し、光導波路内を伝搬する光信号の位相を変化させている。一例では、位相をπ変化させるのに必要な電力（Ｐπ）は３０ｍＷ程度必要であり、小型化する上でさらなる低消費電力化が求められている。 The phase adjuster in the above-mentioned example is a phase adjuster utilizing a thermo-optical effect, and heats an optical waveguide by energizing a metal material (heater) loaded above the optical waveguide and propagates in the optical waveguide. The phase of the optical signal is changed. In one example, the electric power (Pπ) required to change the phase by π is required to be about 30 mW, and further reduction in power consumption is required for miniaturization.
国際公開ＷＯ／２０１８／１７４０８３号公報International Publication WO / 2018/174083
　本発明の目的は、高周波特性の劣化を抑制するとともに、温度変動・温度分布に対する耐性を向上させ、かつ小型化、低消費電力化を図ることができるＩＱ光変調器を提供することにある。 An object of the present invention is to provide an IQ optical modulator capable of suppressing deterioration of high frequency characteristics, improving resistance to temperature fluctuations and temperature distribution, and achieving miniaturization and low power consumption.
　本発明は、このような目的を達成するために、一実施態様は、Ｉチャネル用の第１光変調器とＱチャネル用の第２光変調器とを有するＩＱ光変調器であって、半導体チップの一方の辺から形成された入力光導波路に接続され、前記第１および前記第２光変調器の間に設けられ、前記第１および前記第２光変調器に入力光を分波する第１光分波器と、前記第１および前記第２光変調器からの出力光を合波し、前記半導体チップの前記一方の辺から出力する第１光合波器と、前記第１光変調器の出力と前記第１光合波器との間に挿入された第１位相調整器であって、前記第１光分波器から前記第１光変調器までの光導波路および前記第１光変調器から前記第１光合波器までの光導波路が同一の電極の下部に配置された第１位相調整器と、前記第２光変調器の出力と前記第１光合波器との間に挿入された第２位相調整器であって、前記第１光分波器から前記第２光変調器までの光導波路および前記第２光変調器から前記第１光合波器までの光導波路が同一の電極の下部に配置された第２位相調整器とを備えたことを特徴とする。 In order to achieve such an object, the present invention is an IQ optical modulator having a first optical modulator for an I channel and a second optical modulator for a Q channel, wherein the present invention is a semiconductor. A second optical waveguide connected to an input optical waveguide formed from one side of the chip, provided between the first and second light modulators, and demultiplexing the input light to the first and second light modulators. A first optical modulator that combines the output light from the first and second light modulators and outputs the light from one side of the semiconductor chip, and the first optical modulator. It is a first phase adjuster inserted between the output of the above and the first optical modulator, and is an optical waveguide from the first optical demultiplexer to the first optical modulator and the first optical modulator. The optical waveguide from the first light modulator to the first optical modulator was inserted between the first phase adjuster in which the optical waveguide was arranged below the same electrode, the output of the second light modulator, and the first optical modulator. A second phase adjuster in which the optical waveguide from the first light duplexer to the second light modulator and the optical waveguide from the second light modulator to the first light modulator have the same electrode. It is characterized by having a second phase adjuster arranged at the bottom.
従来の偏波多重型のＩＱ光変調器の一例を示す図である。It is a figure which shows an example of the conventional IQ optical modulator of a polarization multiplex type. 従来の偏波多重型のＩＱ光変調器の他の例を示す図である。It is a figure which shows the other example of the conventional polarization multiplex type IQ light modulator. 本発明の実施例１にかかるＩＱ光変調器を示す図である。It is a figure which shows the IQ light modulator which concerns on Example 1 of this invention. 実施例１にかかるＩＱ光変調器の位相調整器の構造を示す断面図である。It is sectional drawing which shows the structure of the phase adjuster of the IQ light modulator which concerns on Example 1. FIG. 本発明の実施例２にかかるＩＱ光変調器を示す図である。It is a figure which shows the IQ light modulator which concerns on Example 2 of this invention. 本発明の実施例３にかかる偏波多重型のＩＱ光変調器を示す図である。It is a figure which shows the IQ optical modulator of the polarization multiplex type which concerns on Example 3 of this invention. 本発明の実施例４にかかる偏波多重型のＩＱ光変調器を示す図である。It is a figure which shows the IQ optical modulator of the polarization multiplex type which concerns on Example 4 of this invention. 本発明の実施例５にかかる偏波多重型のＩＱ光変調器を示す図である。It is a figure which shows the IQ optical modulator of the polarization multiplex type which concerns on Example 5 of this invention.
　以下、図面を参照しながら本発明の実施形態について詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
　図３に、本発明の実施例１にかかるＩＱ光変調器を示す。ＩＱ光変調器３００は、単一偏波のＩＱ光変調器であって、半導体チップ上にＩチャネル用の光変調器（ＭＺＭ）３０１ＩとＱチャネル用の光変調器（ＭＺＭ）３０１Ｑとからなる入れ子構造を有する。半導体チップの一方の辺から形成された入力光導波路３０２は、光交差導波路３１２を介してＭＺＭ３０１Ｉ、３０１Ｑの間に設けられた光分波器３０４（第１光分波器）に接続される。 FIG. 3 shows the IQ optical modulator according to the first embodiment of the present invention. The IQ optical modulator 300 is a single-polarized IQ optical modulator, which comprises an I-channel optical modulator (MZM) 301I and a Q-channel optical modulator (MZM) 301Q on a semiconductor chip. It has a nested structure. The input optical waveguide 302 formed from one side of the semiconductor chip is connected to the optical demultiplexer 304 (first optical demultiplexer) provided between the MZM 301I and 301Q via the optical cross waveguide 312. ..
　ＩＱ光変調器３００は、光分波器３０４と光合波器３０５との間に、Ｉチャネル用のＭＺＭ３０１Ｉおよび位相調整器３０６Ｉと、Ｑチャネル用のＭＺＭ３０１Ｑおよび位相調整器３０６Ｑとが設けられている。さらに、Ｉチャネル用のＭＺＭ３０１Ｉは、光分波器３０７Ｉと光合波器３０８Ｉとの間に、マッハ・ツェンダー干渉型のアーム導波路（ＭＺ光導波路）３０９Ｉａ，３０９Ｉｂおよび位相調整器３１０Ｉａ，３１０Ｉｂが設けられている。ＭＺ光導波路３０９Ｉａ，３０９Ｉｂに形成された進行波電極は、半導体チップの他方の辺から形成されたＲＦ信号線３１１Ｉａ，３１１Ｉｂに接続され、ＲＦ変調信号が供給される。Ｑチャネル用の構成も同じであるので説明は省略する。入力光３２１は、入力光導波路３０２を経てＭＺＭ３０１ＩとＭＺＭ３０１Ｑにおいて、ＲＦ変調信号によって光変調され、光合波器３０５（第１光合波器）で合波されて、半導体チップの一方の辺から変調出力光３２２として出力される。 The IQ optical modulator 300 is provided with an MZM301I and a phase adjuster 306I for the I channel and an MZM301Q and the phase adjuster 306Q for the Q channel between the light demultiplexer 304 and the optical duplexer 305. .. Further, the MZM301I for the I channel is provided with a Mach-Zehnder interference type arm waveguide (MZ optical waveguide) 309Ia, 309Ib and a phase adjuster 310Ia, 310Ib between the optical demultiplexer 307I and the optical combiner 308I. Has been done. The traveling wave electrode formed on the MZ optical waveguides 309Ia and 309Ib is connected to the RF signal lines 311Ia and 311Ib formed from the other side of the semiconductor chip, and the RF modulation signal is supplied. Since the configuration for the Q channel is the same, the description thereof will be omitted. The input light 321 is photomodulated by an RF modulation signal in MZM301I and MZM301Q via an input optical waveguide 302, is coupled by an optical combiner 305 (first optical combiner), and is modulated and output from one side of a semiconductor chip. It is output as light 322.
　この構成によれば、ＩＱチャネル間で導波路構造が対称であるため、チップ内の温度変動・温度分布に対してチャネル間の特性誤差は小さい。 According to this configuration, since the waveguide structure is symmetric between IQ channels, the characteristic error between channels is small with respect to the temperature fluctuation and temperature distribution in the chip.
　また、位相調整器３０６Ｉには、平行する２つの光導波路、すなわち光分波器３０４から光分波器３０７Ｉに至る入力側の光導波路と、光合波器３０８Ｉから光合波器３０５に至る出力側の光導波路とが、同一の電極の下部に配置されている。同じヒータの加熱領域を２回往復するため、ヒータの長さは、従来と比較して１／２にすることができ、ヒータの信頼性を低下させることなく、ヒータを短尺化することができ、ＩＱ光変調器の小型化にも寄与することができる。 Further, the phase adjuster 306I has two parallel optical waveguides, that is, an optical waveguide on the input side from the optical waveguide 304 to the optical waveguide 307I, and an output side from the optical waveguide 308I to the optical waveguide 305. The optical waveguide of the above is arranged under the same electrode. Since the heating area of the same heater is reciprocated twice, the length of the heater can be halved as compared with the conventional one, and the heater can be shortened without deteriorating the reliability of the heater. , It can also contribute to the miniaturization of the IQ optical modulator.
　光交差導波路３１２は、２つの光導波路の交差部が、光の伝搬方向が直交する十字型に配置された２つの１×１ＭＭＩカプラから構成されている。２つの１×１ＭＭＩカプラは、十字型の平面形状をなし、同一のコア・クラッド構造で形成されており、伝搬方向が直交する２つの光が同一平面で交差する構造になっている。１×１ＭＭＩカプラでは、多数のモードが独立して伝搬するが、それぞれのモードは異なる伝搬速度を有しているため、ある伝搬長において、それらのモードの干渉結果として光が集光する機能を有する。２つのＭＭＩカプラの交差部の中心を、この集光点とすることにより、低損失な光交差導波路として機能させることができる。 The optical waveguide 312 is composed of two 1 × 1 MMI couplers in which the intersections of the two optical waveguides are arranged in a cross shape in which the light propagation directions are orthogonal to each other. The two 1 × 1 MMI couplers have a cross-shaped planar shape and are formed of the same core-clad structure, and have a structure in which two lights having orthogonal propagation directions intersect in the same plane. In a 1x1 MMI coupler, many modes propagate independently, but each mode has a different propagation velocity, so at a certain propagation length, the light is focused as a result of the interference of those modes. Have. By setting the center of the intersection of the two MMI couplers as this condensing point, it can function as a low-loss optical cross-guided path.
　図４に、実施例１にかかるＩＱ光変調器の位相調整器の構造を示す。図３に示したＩＶ－ＩＶ’における断面図である。位相調整器３０６Ｉは、基板であるＳＩ－ＩｎＰ層４０１上に、ｎ－ＩｎＰ層４０２、下部半導体クラッド層４０３、半導体コア層４０４、上部半導体クラッド層４０５が順に積層されている。下部半導体クラッド層４０３から上部半導体クラッド層４０５までは、ドライエッチングによって所望のメサ構造が形成され、２つの光導波路として機能する。２つの光導波路は、有機材料４０６で覆われて平たん化されており、有機材料４０６の上にヒータ４０７となる金属電極が形成されている。 FIG. 4 shows the structure of the phase adjuster of the IQ optical modulator according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line IV-IV'shown in FIG. In the phase adjuster 306I, the n-InP layer 402, the lower semiconductor clad layer 403, the semiconductor core layer 404, and the upper semiconductor clad layer 405 are laminated in this order on the SI-InP layer 401, which is a substrate. A desired mesa structure is formed from the lower semiconductor clad layer 403 to the upper semiconductor clad layer 405 by dry etching, and functions as two optical waveguides. The two optical waveguides are covered with an organic material 406 and flattened, and a metal electrode serving as a heater 407 is formed on the organic material 406.
　光導波路幅は２μｍ、光導波路の中心間隔は４μｍ、ヒータの幅は１０μｍであり、同一のヒータで２つの光導波路を加熱することができる。加熱領域を光が伝搬することにより、光導波路に位相変化が加わるため、同じ加熱領域を２回伝搬することによって、従来の１回伝搬するのに比較して２倍の位相変化を得ることができる。従来の例では、位相をπ変化させるのに必要な電力（Ｐπ）は３０ｍＷであったのに対して、実施例１では約半分にまで削減することができる。 The width of the optical waveguide is 2 μm, the distance between the centers of the optical waveguide is 4 μm, and the width of the heater is 10 μm, so that two optical waveguides can be heated by the same heater. Since light propagates in the heated region, a phase change is applied to the optical waveguide. Therefore, by propagating twice in the same heated region, it is possible to obtain twice the phase change as compared with the conventional single propagation. can. In the conventional example, the electric power (Pπ) required to change the phase by π is 30 mW, but in the first embodiment, it can be reduced to about half.
　図５に、本発明の実施例２にかかるＩＱ光変調器を示す。ＩＱ光変調器５００は、単一偏波のＩＱ光変調器であって、半導体チップ上にＩチャネル用のＭＺＭ５０１ＩとＱチャネル用のＭＺＭ５０１Ｑとからなる入れ子構造を有する。半導体チップの一方の辺から形成された入力光導波路５０２は、光交差導波路５１２を介してＭＺＭ５０１Ｉ、５０１Ｑの間に設けられた光分波器５０４（第１光分波器）に接続される。 FIG. 5 shows the IQ optical modulator according to the second embodiment of the present invention. The IQ optical modulator 500 is a single-polarized IQ optical modulator, which has a nested structure of MZM501I for I-channel and MZM501Q for Q-channel on a semiconductor chip. The input optical waveguide 502 formed from one side of the semiconductor chip is connected to the optical demultiplexer 504 (first optical demultiplexer) provided between the MZM501I and 501Q via the optical cross waveguide 512. ..
　ＩＱ光変調器５００は、光分波器５０４と光合波器５０５との間に、Ｉチャネル用のＭＺＭ５０１Ｉおよび位相調整器５０６Ｉと、Ｑチャネル用のＭＺＭ５０１Ｑおよび位相調整器５０６Ｑとが設けられている。さらに、Ｉチャネル用のＭＺＭ５０１Ｉには、ＭＺＭ５０１Ｉ，５０１Ｑの間に光分波器５０７Ｉ（第２光分波器）および位相調整器５１０Ｉａ，５１０Ｉｂが設けられ、その出力側の光導波路を１８０°折り返して、マッハ・ツェンダー干渉型のアーム導波路（ＭＺ光導波路）５０９Ｉａ，５０９Ｉｂに接続している。すなわち、光分波器５０７Ｉの光伝搬方向とＭＺ光導波路５０９Ｉａ，５０９Ｉｂの光伝搬方向が反対方向である。なお、位相調整器５１０Ｉａ，５１０ＩｂからＭＺ光導波路５０９Ｉａ，５０９Ｉｂまでの光導波路の長さが等しくなるように、折り返し部分の内側の光導波路には、折り曲げ部を設けている。ＭＺ光導波路５０９Ｉａ，５０９Ｉｂの出力は、光合波器５０８Ｉで合波され、位相調整器５０６Ｉに入力される。 The IQ optical modulator 500 is provided with an MZM501I and a phase adjuster 506I for an I channel and an MZM501Q and a phase adjuster 506Q for a Q channel between the light demultiplexer 504 and the optical combiner 505. .. Further, the MZM501I for the I channel is provided with an optical demultiplexer 507I (second optical demultiplexer) and phase adjusters 510Ia and 510Ib between the MZM501I and 501Q, and the optical waveguide on the output side is folded back by 180 °. It is connected to the Mach-Zehnder interference type arm waveguide (MZ optical waveguide) 509Ia, 509Ib. That is, the light propagation direction of the light demultiplexer 507I and the light propagation direction of the MZ optical waveguides 509Ia and 509Ib are opposite to each other. The optical waveguide inside the folded portion is provided with a bent portion so that the lengths of the optical waveguides from the phase adjusters 510Ia and 510Ib to the MZ optical waveguides 509Ia and 509Ib are equal. The outputs of the MZ optical waveguides 509Ia and 509Ib are combined by the optical combiner 508I and input to the phase adjuster 506I.
　ＭＺ光導波路５０９Ｉａ，５０９Ｉｂに形成された進行波電極は、半導体チップの他方の辺から形成されたＲＦ信号線５１１Ｉａ，５１１Ｉｂに接続され、ＲＦ変調信号が供給される。Ｑチャネル用の構成も同じであるので説明は省略する。入力光５２１は、入力光導波路５０２を経てＭＺＭ５０１ＩとＭＺＭ５０１Ｑにおいて、ＲＦ変調信号によって光変調され、光合波器５０５（第１光合波器）で合波されて、半導体チップの一方の辺から変調出力光５２２として出力される。 The traveling wave electrode formed on the MZ optical waveguide 509Ia, 509Ib is connected to the RF signal line 511Ia, 511Ib formed from the other side of the semiconductor chip, and the RF modulation signal is supplied. Since the configuration for the Q channel is the same, the description thereof will be omitted. The input light 521 is photomodulated by the RF modulation signal in the MZM501I and MZM501Q via the input optical waveguide 502, combined by the optical combiner 505 (first optical combiner), and modulated and output from one side of the semiconductor chip. It is output as light 522.
　この構成によれば、位相調整器５１０Ｉａ，５１０ＩｂをＭＺＭ５０１Ｉ，５０１Ｑの間に設けたので、実施例１と比較すると、ＲＦ信号線５１１Ｉａ，５１１Ｉｂの線路長を短尺化することができるとともに、半導体チップの短尺化も図ることができる。 According to this configuration, since the phase adjusters 510Ia and 510Ib are provided between the MZM501I and 501Q, the line lengths of the RF signal lines 511Ia and 511Ib can be shortened as compared with the first embodiment, and the semiconductor chip can be shortened. Can also be shortened.
　さらに、位相調整器５０６Ｉには、平行する２つの光導波路、すなわち光分波器５０４から光分波器５０７Ｉに至る入力側の光導波路と、光合波器５０８Ｉから光合波器５０５に至る出力側の光導波路とが、同一の電極の下部に配置されている。同じヒータの加熱領域を２回往復するため、ヒータの長さは、従来と比較して１／２にすることができ、ヒータの信頼性を低下させることなく、ヒータを短尺化することができ、ＩＱ光変調器の小型化にも寄与することができる。 Further, the phase adjuster 506I has two parallel optical waveguides, that is, an optical waveguide on the input side from the optical waveguide 504 to the optical waveguide 507I, and an output side from the optical waveguide 508I to the optical waveguide 505. The optical waveguide of the above is arranged under the same electrode. Since the heating area of the same heater is reciprocated twice, the length of the heater can be halved as compared with the conventional one, and the heater can be shortened without deteriorating the reliability of the heater. , It can also contribute to the miniaturization of the IQ optical modulator.
　図６に、本発明の実施例３にかかる偏波多重型のＩＱ光変調器を示す。偏波多重型のＩＱ光変調器６００は、半導体チップ上に、図５に示した実施例２のＩＱ光変調器５００を、Ｘ偏波チャネル用およびＹ偏波チャネル用に２つ並列に集積して、入れ子構造にしている。半導体チップの一方の辺の中央から形成された入力光導波路６０２は、光分波器６０３に接続され、その出力はＸ偏波チャネル用のＭＺＭ６０１ＸとＹ偏波チャネル用のＭＺＭ６０１Ｙに入力される。 FIG. 6 shows a polarization-multiplexed IQ optical modulator according to the third embodiment of the present invention. In the polarization multiplexing type IQ optical modulator 600, two IQ optical modulators 500 of Example 2 shown in FIG. 5 are integrated in parallel on a semiconductor chip, one for the X polarization channel and the other for the Y polarization channel. It has a nested structure. The input optical waveguide 602 formed from the center of one side of the semiconductor chip is connected to the light demultiplexer 603, and its output is input to the MZM601X for the X polarization channel and the MZM601Y for the Y polarization channel.
　光分波器６０３の出力には、光交差導波路６１２Ｘ，６１２Ｙを介して、光分波器６０４Ｘ，６０４Ｙが接続され、さらに、その出力にはＭＺＭ６０１ＸＩ，６０１ＸＱとＭＺＭ６０１ＹＩ，６０１ＹＱのそれぞれが接続される。 The optical demultiplexers 604X and 604Y are connected to the output of the optical demultiplexer 603 via optical cross-guide paths 612X and 612Y, and MZM601XI, 601XQ and MZM601YI, 601YQ are connected to the outputs, respectively. To.
　Ｘ偏波チャネル用のＭＺＭ６０１Ｘは、光分波器６０４Ｘと光合波器６０５Ｘとの間に、Ｉチャネル用のＭＺＭ６０１ＸＩおよび位相調整器６０６ＸＩと、Ｑチャネル用のＭＺＭ６０１ＸＱおよび位相調整器６０６ＸＱとが設けられている。さらに、Ｉチャネル用のＭＺＭ６０１ＸＩには、ＭＺＭ６０１ＸＩ，６０１ＸＱの間に光分波器６０７ＸＩおよび位相調整器６１０ＸＩａ，６１０ＸＩｂが設けられ、その出力側の光導波路を１８０°折り返して、ＭＺ光導波路６０９ＸＩａ，６０９ＸＩｂに接続している。なお、位相調整器６１０ＸＩａ，６１０ＸＩｂからＭＺ光導波路６０９ＸＩａ，６０９ＸＩｂまでの光導波路の長さが等しくなるように、折り返し部分の内側の光導波路には、折り曲げ部を設けている。ＭＺ光導波路６０９ＸＩａ，６０９ＸＩｂの出力は、光合波器６０８ＸＩで合波され、位相調整器６０６ＸＩに入力される。位相調整器６０６ＸＩ，６０６ＸＱの出力が、光合波器６０５Ｘにて合波されて変調出力光６２２Ｘとして出力される。 The MZM601X for the X polarization channel is provided with the MZM601XI and the phase adjuster 606XI for the I channel and the MZM601XQ and the phase adjuster 606XQ for the Q channel between the light demultiplexer 604X and the optical combiner 605X. ing. Further, the MZM601XI for the I channel is provided with an optical demultiplexer 607XI and a phase adjuster 610XIa, 610XIb between the MZM601XI and 601XIb, and the optical waveguide on the output side thereof is folded back 180 ° to form the MZ optical waveguide 609XIa, 609XIb. Is connected to. The optical waveguide inside the folded portion is provided with a bent portion so that the lengths of the optical waveguides from the phase adjusters 610XIa and 610XIb to the MZ optical waveguide 609XIa and 609XIb are equal. The outputs of the MZ optical waveguides 609XIa and 609XIb are combined by the optical combiner 608XI and input to the phase adjuster 606XI. The outputs of the phase adjusters 606XI and 606XQ are combined by the optical combiner 605X and output as the modulated output light 622X.
　ＭＺ光導波路６０９ＸＩａ，６０９ＸＩｂに形成された進行波電極は、半導体チップの他方の辺から形成されたＲＦ信号線６１１ＸＩａ，６１１ＸＩｂに接続され、ＲＦ変調信号が供給される。Ｑチャネル用の構成も同じであるので説明は省略する。また、Ｙ偏波チャネル用のＭＺＭ６０１ＹもＸ偏波チャネル用のＭＺＭ６０１Ｘと同じ構造を有するので説明は省略する。 The traveling wave electrode formed on the MZ optical waveguide 609XIa, 609XIb is connected to the RF signal line 611XIa, 611XIb formed from the other side of the semiconductor chip, and the RF modulation signal is supplied. Since the configuration for the Q channel is the same, the description thereof will be omitted. Further, since the MZM601Y for the Y polarization channel has the same structure as the MZM601X for the X polarization channel, the description thereof will be omitted.
　入力光６２１は、入力光導波路６０２を経て光分波器６０３で分岐され、Ｘ，Ｙ偏波の各チャネル光は、ＭＺＭ６０１ＸとＭＺＭ６０１Ｙにおいて、ＲＦ変調信号によって光変調され、半導体チップの一方の辺から変調出力光６２２Ｘ、６２２Ｙとして出力される。 The input light 621 is branched by the optical demultiplexer 603 via the input optical waveguide 602, and each channel light of X and Y polarization is photomodulated by an RF modulation signal in MZM601X and MZM601Y, and one side of the semiconductor chip. Is output as modulated output light 622X, 622Y.
　この構成によれば、位相調整器６１０ＸＩａ，６１０ＸＩｂをＭＺＭ６０１ＸＩ，６０１ＸＱの間に設けたので、ＲＦ信号線６１１ＸＩａ，６１１ＸＩｂの線路長を短尺化することができるとともに、半導体チップの短尺化も図ることができる。 According to this configuration, since the phase adjusters 610XIa and 610XIb are provided between the MZM601XI and 601XQ, the line length of the RF signal lines 611XIa and 611XIb can be shortened and the semiconductor chip can be shortened. can.
　さらに、位相調整器６０６ＸＩ，６０６ＸＱには、平行する２つの光導波路、すなわち光分波器６０４Ｘから光分波器６０７ＸＩ，６０７ＸＱに至る入力側の光導波路と、光合波器６０８ＸＩ，６０８ＸＱから光合波器６０５Ｘに至る出力側の光導波路とが、同一の電極の下部に配置されている。同じヒータの加熱領域を２回往復するため、ヒータの長さは、従来と比較して１／２にすることができ、ヒータの信頼性を低下させることなく、ヒータを短尺化することができ、ＩＱ光変調器の小型化にも寄与することができる。 Further, the phase adjusters 606XI and 606XQ have two parallel optical waveguides, that is, an optical waveguide on the input side from the optical demultiplexer 604X to the optical demultiplexer 607XI and 607XQ, and the optical waveguide from the optical combiner 608XI and 608XQ. The output-side optical waveguide leading to the device 605X is located below the same electrode. Since the heating area of the same heater is reciprocated twice, the length of the heater can be halved as compared with the conventional one, and the heater can be shortened without deteriorating the reliability of the heater. , It can also contribute to the miniaturization of the IQ optical modulator.
　図７に、本発明の実施例４にかかる偏波多重型のＩＱ光変調器を示す。偏波多重型のＩＱ光変調器７００は、半導体チップ上に、図５に示した実施例２のＩＱ光変調器５００を、Ｘ偏波チャネル用およびＹ偏波チャネル用に２つ並列に集積して、入れ子構造にしている。半導体チップの一方の辺の中央から形成された入力光導波路７０２は、光分波器７０３に接続され、その出力はＸ偏波チャネル用のＭＺＭ７０１ＸとＹ偏波チャネル用のＭＺＭ７０１Ｙに入力される。 FIG. 7 shows a polarization-multiplexed IQ optical modulator according to the fourth embodiment of the present invention. In the polarization multiplexing type IQ optical modulator 700, two IQ optical modulators 500 of Example 2 shown in FIG. 5 are integrated in parallel on a semiconductor chip, one for the X polarization channel and the other for the Y polarization channel. It has a nested structure. The input optical waveguide 702 formed from the center of one side of the semiconductor chip is connected to the light demultiplexer 703, and its output is input to the MZM701X for the X polarization channel and the MZM701Y for the Y polarization channel.
　光分波器７０３の出力には、光交差導波路７１２Ｘ，７１２Ｙを介して、光分波器７０４Ｘ，７０４Ｙが接続され、さらに、その出力にはＭＺＭ７０１ＸＩ，７０１ＸＱとＭＺＭ７０１ＹＩ，７０１ＹＱのそれぞれが接続される。ＭＺＭ７０１ＸＩ，７０１ＸＱの出力は、位相調整器７０６ＸＩ，７０６ＸＱを介して光合波器７０５Ｘにて合波され、変調出力光７２２Ｘとして出力される。ＭＺＭ７０１ＸＩ，７０１ＸＱの構成は、図６に示した実施例３のＭＺＭ６０１ＹＩ，６０１ＹＱと同じであるので説明は省略する。 An optical demultiplexer 704X, 704Y is connected to the output of the optical demultiplexer 703 via an optical cross-guided waveguide 712X, 712Y, and further, MZM701XI, 701XQ and MZM701YI, 701YQ are connected to the output, respectively. To. The output of the MZM701XI, 701XQ is combined by the optical combiner 705X via the phase adjuster 706XI, 706XQ, and is output as the modulated output light 722X. Since the configurations of the MZM701XI and 701XQ are the same as those of the MZM601YI and 601YQ of the third embodiment shown in FIG. 6, the description thereof will be omitted.
　実施例３との相違点は、位相調整器７０６ＸＩと光合波器７０５Ｘとの間に、ダミー光交差導波路７１３Ｘが挿入されていることである。この構成によれば、ＸＹチャネルおよびＩＱチャネル間で、光導波路の交差数が等しくなるため、光学特性のチャネル間における特性差を抑制することができる。 The difference from the third embodiment is that a dummy optical cross-guided waveguide 713X is inserted between the phase adjuster 706XI and the optical combiner 705X. According to this configuration, since the number of intersections of the optical waveguide is equal between the XY channel and the IQ channel, it is possible to suppress the characteristic difference between the channels of the optical characteristics.
　図８に、本発明の実施例５にかかる偏波多重型のＩＱ光変調器を示す。偏波多重型のＩＱ光変調器８００は、半導体チップ上に、Ｘ偏波チャネル用のＭＺＭ８０１ＸおよびＹ偏波チャネル用のＭＺＭ８０１Ｙとして、図６に示した実施例３のＸ偏波チャネル用のＭＺＭ６０１ＸおよびＹ偏波チャネル用のＭＺＭ６０１Ｙ、または図７に示した実施例４のＸ偏波チャネル用のＭＺＭ７０１ＸおよびＹ偏波チャネル用のＭＺＭ７０１Ｙを備えた入れ子構造にしている。実施例３および実施例４との相違点は、入力部に可変分岐回路を設けたことにある。 FIG. 8 shows a polarization-multiplexed IQ optical modulator according to the fifth embodiment of the present invention. The polarization multiplex IQ optical modulator 800 is the MZM801X for the X polarization channel and the MZM801Y for the Y polarization channel on the semiconductor chip, and the MZM601X for the X polarization channel and the MZM601X for the X polarization channel shown in FIG. It has a nested structure including MZM601Y for the Y polarization channel, or MZM701X for the X polarization channel of Example 4 shown in FIG. 7 and MZM701Y for the Y polarization channel. The difference between the third embodiment and the fourth embodiment is that a variable branch circuit is provided in the input section.
　可変分岐回路は、入力光導波路８０２に、１入力２出力型光分波器８３１、ＤＣ位相調整器８３２ａ，８３２ｂ、および２入力２出力型光合分波器８３３が順に接続された構成を有している。 The variable branch circuit has a configuration in which a 1-input 2-output optical demultiplexer 831, a DC phase adjuster 832a, 832b, and a 2-input 2-output optical combine demultiplexer 833 are connected in order to the input optical waveguide 802. ing.
　従来、Ｘ偏波、Ｙ偏波のチャネル間の光挿入損失差は、ＰＤＬ（polarization dependent loss：偏波依存損失）として仕様が決められている。しかし、加工プロセス等に起因した不均一化によって、偏波多重型のＩＱ光変調器においては、ＰＤＬが増大することが課題として挙げられていた。ＰＤＬの補償機構としては、従来、偏波チャネルごとにＶＯＡ（可変光減衰器）を用いて損失差を補償していた。しかしながら、ＶＯＡによる補償機構では、光パワー強度の大きい方のチャネルの光強度を減衰させて調整するので、原理的に過剰な光損失が生じていた。 Conventionally, the specification of the difference in optical insertion loss between X-polarized and Y-polarized channels is determined as PDL (polarization dependent loss). However, it has been mentioned as a problem that the PDL increases in the polarization multiplex IQ optical modulator due to the non-uniformity caused by the processing process or the like. As a PDL compensation mechanism, conventionally, a VOA (variable optical attenuator) has been used for each polarization channel to compensate for the loss difference. However, in the compensation mechanism by VOA, the optical intensity of the channel having the larger optical power intensity is attenuated and adjusted, so that excessive optical loss occurs in principle.
　実施例５の可変分岐回路は、分岐比を任意に調整することができる、光パワートリミング機構として機能する。これにより、過剰な損失が無く光強度を維持したままＰＤＬ補償を行うことができる。 The variable branch circuit of the fifth embodiment functions as an optical power trimming mechanism capable of arbitrarily adjusting the branch ratio. As a result, PDL compensation can be performed while maintaining the light intensity without excessive loss.

Claims (6)

  1. 　Ｉチャネル用の第１光変調器とＱチャネル用の第２光変調器とを有するＩＱ光変調器であって、
    　半導体チップの一方の辺から形成された入力光導波路に接続され、前記第１および前記第２光変調器の間に設けられ、前記第１および前記第２光変調器に入力光を分波する第１光分波器と、
    　前記第１および前記第２光変調器からの出力光を合波し、前記半導体チップの前記一方の辺から出力する第１光合波器と、
    　前記第１光変調器の出力と前記第１光合波器との間に挿入された第１位相調整器であって、前記第１光分波器から前記第１光変調器までの光導波路および前記第１光変調器から前記第１光合波器までの光導波路が同一の電極の下部に配置された第１位相調整器と、
    　前記第２光変調器の出力と前記第１光合波器との間に挿入された第２位相調整器であって、前記第１光分波器から前記第２光変調器までの光導波路および前記第２光変調器から前記第１光合波器までの光導波路が同一の電極の下部に配置された第２位相調整器と
    　を備えたことを特徴とするＩＱ光変調器。     An IQ optical modulator having a first optical modulator for the I channel and a second optical modulator for the Q channel.
    It is connected to an input optical waveguide formed from one side of a semiconductor chip, is provided between the first and second light modulators, and demultiplexes the input light to the first and second light modulators. The first optical waveguide and
    A first optical combiner that combines the output light from the first and second light modulators and outputs it from one side of the semiconductor chip.
    A first phase adjuster inserted between the output of the first optical modulator and the first optical modulator, which is an optical waveguide from the first optical duplexer to the first optical modulator. A first phase adjuster in which an optical waveguide from the first light modulator to the first optical modulator is arranged under the same electrode, and
    A second phase adjuster inserted between the output of the second light modulator and the first light modulator, which is an optical waveguide from the first light duplexer to the second light modulator. An IQ optical modulator characterized in that an optical waveguide from the second optical modulator to the first optical modulator is provided with a second phase adjuster arranged under the same electrode.
  2. 　前記入力光導波路は、前記第１または前記第２位相調整器のいずれか一方と前記第１光合波器との間の光導波路と交差し、２つの光導波路の交差部が、光の伝搬方向が直交する十字型に配置された２つの１×１ＭＭＩカプラから構成されていることを特徴とする請求項１に記載のＩＱ光変調器。 The input optical waveguide intersects the optical waveguide between either one of the first or the second phase adjuster and the first optical waveguide, and the intersection of the two optical waveguides is the light propagation direction. The IQ optical modulator according to claim 1, wherein the IQ optical modulators are composed of two 1 × 1 MMI couplers arranged in an orthogonal cross shape.
  3. 　前記第１および前記第２光変調器のそれぞれは、前記第１光分波器で分波された光を２つのアーム光導波路に分岐する第２光分波器を、前記第１および前記第２光変調器の間に有し、前記第２光分波器の光伝搬方向と前記第１および前記第２光変調器の光伝搬方向が反対方向であることを特徴とする請求項１または２に記載のＩＱ光変調器。 Each of the first and second optical modulators has a second optical duplexer that splits the light demultiplexed by the first optical duplexer into two arm optical waveguides. 1. 2. The IQ optical modulator according to 2.
  4. 　前記第１または前記第２位相調整器の他方と前記第１光合波器との間の光導波路に、光の伝搬方向が直交する十字型に配置された２つの１×１ＭＭＩカプラが構成されていることを特徴とする請求項２または３に記載のＩＱ光変調器。 Two 1 × 1 MMI couplers arranged in a cross shape in which the light propagation directions are orthogonal to each other are configured in the optical waveguide between the other of the first or second phase adjuster and the first optical modulator. The IQ optical modulator according to claim 2 or 3, wherein the IQ optical modulator is provided.
  5. 　偏波多重型のＩＱ光変調器であって、
    　前記半導体チップ上に並列に集積され、Ｘ偏波チャネル用のＩＱ光変調器およびＹ偏波チャネル用のＩＱ光変調器として、請求項１ないし４のいずれか１項に記載の２つのＩＱ光変調器と、
    　前記半導体チップの一方の辺から形成された入力光導波路に接続され、前記２つのＩＱ光変調器のそれぞれの第１光分波器に入力光を分波する第３光分波器と
    　を備えたことを特徴とするＩＱ光変調器。     It is a polarization-multiplexed IQ optical modulator,
    The two IQ light according to any one of claims 1 to 4 as an IQ optical modulator for an X-polarized channel and an IQ optical modulator for a Y-polarized channel, which are integrated in parallel on the semiconductor chip. Modulator and
    A third optical demultiplexer connected to an input optical waveguide formed from one side of the semiconductor chip and demultiplexing the input light into the first optical demultiplexer of each of the two IQ light modulators is provided. An IQ optical modulator characterized by the fact that.
  6. 　偏波多重型のＩＱ光変調器であって、
    　前記半導体チップ上に並列に集積され、Ｘ偏波チャネル用のＩＱ光変調器およびＹ偏波チャネル用のＩＱ光変調器として、請求項１ないし４のいずれか１項に記載の２つのＩＱ光変調器と、
    　前記半導体チップの一方の辺から形成された入力光導波路に接続された可変分岐回路とを備え、
    　前記可変分岐回路は、前記入力光導波路に接続された１入力２出力型光分波器、２つのＤＣ位相調整器、および前記２つのＩＱ光変調器のそれぞれの第１光分波器に入力光を分波する２入力２出力型光合分波器が順に接続されていることを特徴とするＩＱ光変調器。     It is a polarization-multiplexed IQ optical modulator,
    The two IQ light according to any one of claims 1 to 4 as an IQ optical modulator for an X-polarized channel and an IQ optical modulator for a Y-polarized channel, which are integrated in parallel on the semiconductor chip. Modulator and
    A variable branch circuit connected to an input optical waveguide formed from one side of the semiconductor chip is provided.
    The variable branch circuit is input to the first optical demultiplexer of each of the 1-input 2-output optical duplexer connected to the input optical waveguide, the two DC phase adjusters, and the two IQ optical modulators. An IQ optical modulator characterized in that two-input, two-output optical waveguides that demultiplex light are connected in order.
PCT/JP2020/041612 2020-11-06 2020-11-06 Iq optical modulator WO2022097289A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180267340A1 (en) * 2017-03-15 2018-09-20 Elenion Technologies, Llc Bias control of optical modulators
WO2018174083A1 (en) * 2017-03-22 2018-09-27 日本電信電話株式会社 Iq optical modulator
JP2018534627A (en) * 2015-11-20 2018-11-22 オクラロ テクノロジー リミテッド Optical modulation device
JP2019152732A (en) * 2018-03-02 2019-09-12 富士通オプティカルコンポーネンツ株式会社 Light modulator and optical transceiver module using the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018534627A (en) * 2015-11-20 2018-11-22 オクラロ テクノロジー リミテッド Optical modulation device
US20180267340A1 (en) * 2017-03-15 2018-09-20 Elenion Technologies, Llc Bias control of optical modulators
WO2018174083A1 (en) * 2017-03-22 2018-09-27 日本電信電話株式会社 Iq optical modulator
JP2019152732A (en) * 2018-03-02 2019-09-12 富士通オプティカルコンポーネンツ株式会社 Light modulator and optical transceiver module using the same

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