WO2017022246A1 - 光変調器 - Google Patents
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- WO2017022246A1 WO2017022246A1 PCT/JP2016/003589 JP2016003589W WO2017022246A1 WO 2017022246 A1 WO2017022246 A1 WO 2017022246A1 JP 2016003589 W JP2016003589 W JP 2016003589W WO 2017022246 A1 WO2017022246 A1 WO 2017022246A1
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- 230000003287 optical effect Effects 0.000 title claims abstract description 269
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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
- G02F1/015—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 based on semiconductor elements having potential barriers, e.g. having a PN or PIN junction
- G02F1/025—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 based on semiconductor elements having potential barriers, e.g. having a PN or PIN junction in an optical waveguide structure
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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
- G02F1/21—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 by interference
- G02F1/225—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 by interference in an optical waveguide structure
-
- 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
- G02F1/21—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 by interference
- G02F1/225—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 by interference in an optical waveguide structure
- G02F1/2255—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 by interference in an optical waveguide structure controlled by a high-frequency electromagnetic component in an electric waveguide structure
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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
- G02F1/21—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 by interference
- G02F1/212—Mach-Zehnder type
-
- 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
- G02F2203/00—Function characteristic
- G02F2203/50—Phase-only modulation
Definitions
- the present invention relates to an optical modulator used in an optical communication system and an optical information processing system.
- the present invention relates to a structure for providing an optical modulator capable of suppressing a chirp generated at the time of phase modulation of the optical modulator and outputting modulated light with good waveform quality.
- a Mach-Zehnder (MZ) type optical modulator branches light incident on an optical waveguide on the input side into two optical waveguides (arms) at an intensity of 1: 1, and propagates the branched light by a certain length After having it, it has a structure which combines again and outputs.
- a phase modulation unit provided in the two branched optical waveguides, the interference condition of the light beams to be multiplexed is changed, and the intensity and phase of the output light are modulated. be able to.
- a dielectric such as LiNbO 3 or a semiconductor such as InP, GaAs, Si or the like is used as a material forming the optical waveguide of the phase modulation unit, and a modulated electrical signal is input to electrodes disposed in the vicinity of these optical waveguides.
- a voltage By applying a voltage to the optical waveguide, the phase of light propagating through the optical waveguide is changed.
- LiNbO 3 mainly uses Pockels effect
- InP and GaAs mainly use Pockels effect and Quantum Confined Stark Effect (QCSE)
- Si mainly uses carrier plasma effect.
- an optical modulator with a high modulation speed and a low driving voltage is required.
- the speed of the light propagating through the optical waveguide is matched with the speed of the modulated electrical signal, and the progress is made to interact with the light while propagating the electrical signal.
- Wave electrodes are required.
- An optical modulator in which the traveling wave electrode has a length of several millimeters to several tens of millimeters has been put to practical use. (For example, Non-Patent Document 1)
- an electrode structure and an optical waveguide structure with low loss and little reflection are required so that the electric signal and the light propagating in the waveguide can be propagated without reducing the intensity.
- Si optical modulators in which the optical waveguide is made of Si.
- the Si light modulator is composed of an SOI (Silicon on Insulator) substrate in which a thin film of Si is stuck on an oxide film (BOX) layer obtained by thermally oxidizing the surface of the Si substrate.
- a thin Si film is processed into a thin wire so that light can be guided to the SOI layer to form an optical waveguide, and then a dopant is injected to become a p-type / n-type semiconductor, depositing SiO 2 to be a light cladding layer, an electrode To form a Si light modulator.
- the optical waveguide needs to be designed and processed so as to reduce the light loss. Therefore, it is necessary to design and process the p-type / n-type doping and electrodes so as to suppress the occurrence of light loss as well as to minimize reflection and loss of high-speed electrical signals.
- FIG. 1 shows a cross-sectional structural view of an optical waveguide which is a basis of a conventional Si light modulator.
- the optical waveguide of this Si light modulator is composed of the Si layer 2 sandwiched between the upper and lower SiO 2 cladding layers 1 and 3.
- the Si fine wire portion for confining light in the center of the figure of the Si layer 2 has a cross-sectional structure called a rib waveguide which has a difference in thickness from the periphery.
- the optical waveguide 7 is used to confine light propagating in the direction perpendicular to the paper surface by using the refractive index difference from the surrounding SiO 2 cladding layers 1 and 3. Configure.
- a high concentration p-type semiconductor layer 211 and a high concentration n-type semiconductor layer 214 are provided in the slab region 202 on both sides of the optical waveguide 7. Furthermore, a pn junction structure consisting of a medium concentration p-type semiconductor layer 212 and a medium concentration n-type semiconductor layer 213 is formed in the core central portion of the optical waveguide 7 by doping. Is applied.
- the pn junction structure of the medium concentration p-type semiconductor layer 212 and the medium concentration n-type semiconductor layer 213 may be a pin structure sandwiching an i-type (intrinsic) semiconductor which is not doped in between.
- the optical waveguide 7 propagates light along the pn junction (in the direction perpendicular to the drawing).
- metal electrodes in contact with the high concentration semiconductor layers 211 and 214 at both ends are provided. From this metal electrode, a reverse bias electric field (an electric field directed from the right to the left in FIG. 1) is applied to the pn junction together with the RF (high frequency) modulated electric signal.
- the waveguide dimensions can not be determined uniquely because they depend on the refractive index of the core / cladding material.
- This electrode is provided along the two optical waveguides constituting the two arms of the Mach-Zehnder type optical modulator, and fixed with two RF electrodes for applying a pair of differential signal voltages for modulation. And at least one fixed potential electrode for applying a potential.
- the fixed potential electrode is called a DC electrode because it is disposed between two RF electrodes in the case of a single electrode structure to provide a DC bias potential.
- the fixed potential electrode is disposed between the two RF electrodes and outside the two RF electrodes to provide a ground potential (ground potential) of 0 V so that the ground (GND) electrode and be called.
- FIG. 2 is a plan view of a Si optical modulator which is a conventional single-electrode type Mach-Zehnder modulator
- FIG. 3 is a sectional structural view taken along the line III-III. (For example, refer to non-patent document 2)
- the optical input from the left side is branched into the optical waveguides 7a and 7b, and modulated electric signal (RF signal) applied between the upper and lower RF electrodes 5a and 5b and the central DC electrode 6 After being phase-modulated, they are combined, and are optically output as modulated light from the right end to constitute a single electrode type Mach-Zehnder modulator.
- RF signal modulated electric signal
- Two high frequency lines (RF electrodes 5 a and 5 b) for inputting a pair of differential modulation electric signals (RF signals) are provided on the left and right sides on the cladding layer 3, and the center in the cladding layer 3 is , DC electrode 6 for applying a common bias voltage.
- two optical waveguides 7a and 7b are provided with the DC electrode 6 interposed therebetween.
- pn junction structures are formed symmetrically in the left-right direction.
- the RF electrodes 5a and 5b are electrically connected to the high concentration p-type semiconductor layer 211 through the vias 4 (through electrodes).
- the DC electrode 6 is connected to the central high concentration n-type semiconductor layer 214, and a positive voltage is applied to the DC electrode 6 with respect to the RF electrodes 5a and 5b to reverse the left and right pn junctions. A bias can be applied.
- These electrodes and the semiconductor layer are electrically connected by one or more vias 4 as in the following.
- FIG. 4 shows the doping state (a) of the semiconductor in the III-III cross section and the band diagram (b) at the time of light modulation.
- the RF electrode and the DC electrode are electrically independent, and when applying a reverse bias to the pn junction, it is not necessary to positively apply the bias voltage to the RF electrode. . Therefore, there is an advantage that the configuration can be simplified, such as eliminating the need for bias tees for applying a bias to the RF electrode, a capacitor for a DC block provided between the driver IC and the RF electrode, and the like.
- a bias voltage applied to the DC electrode can apply a reverse bias to the pn junction by applying a negative voltage to the RF electrode.
- FIG. 5 shows a plan view of a Si optical modulator that constitutes a conventional dual electrode type Mach-Zehnder modulator
- FIG. 6 shows a partial cross-sectional structural view of FIG.
- the optical input from the left side is branched into the optical waveguides 7a and 7b, phase-modulated by the modulated electrical signal (RF signal) applied to the upper and lower RF electrodes 15a and 15b, and then combined More light is output to constitute a dual electrode type Mach-Zehnder modulator.
- RF signal modulated electrical signal
- FIG. 6 In the VI-VI partial cross-sectional structure view of FIG. 5 shown in FIG. 6, one of the optical waveguide 7a having the same cross-sectional structure as FIG. 1 and one of the high frequency lines for inputting a differential modulation electrical signal (RF signal)
- RF signal differential modulation electrical signal
- a cross section of a portion having (the RF electrode 15a) and the ground electrodes 16a and 16c provided so as to sandwich the RF electrode 15a is illustrated.
- a pn junction structure is formed in the optical waveguide 7a provided in the Si layer 2 between the RF electrode 15a and the ground electrode 16a.
- the RF electrode 15 a and the ground electrode 16 a on the cladding layer 3 are electrically connected to the high concentration n-type semiconductor layer 214 and the high concentration p-type semiconductor layer 211 of the Si layer 2 through the vias 4, respectively.
- the central ground electrode 16c (right side in FIG. 6) in FIG. 5 is not in direct contact with the semiconductor layer, but is at the potential of ground (ground).
- the electrodes 16a and 16c form a high-frequency transmission line of a ground-signal-ground (GSG) structure.
- GSG ground-signal-ground
- the characteristic impedance of the transmission line can be adjusted and the transmission characteristic can be improved.
- the RF signal line is surrounded by the ground electrode, it is possible to form an optical modulator with less signal leakage and less crosstalk and propagation loss.
- the structure of the electrode and the semiconductor region is the same as for the optical waveguide 7b.
- the semiconductor region corresponding to the optical waveguide 7b is formed separately from the semiconductor region corresponding to the optical waveguide 7a. They are disposed symmetrically in the vertical direction (left and right in FIG. 6) of FIG. 5 with respect to the center line of the central ground electrode 16c, and the doping state is also symmetrical.
- the characteristic impedance of the Si optical modulator as a high frequency transmission line is largely affected by the capacitance of the pn junction of the Si layer.
- adjustment of the characteristic impedance is relatively easy by adjusting the capacitance (capacitance) between the RF electrode 15a and the ground electrode 16c. It is possible to make it about 100 ⁇ .
- a bias voltage added to the RF signal to the RF electrode can apply a reverse bias to the pn junction by applying a negative voltage to the ground electrode.
- the chirp of the MZ optical modulator is a modulation that occurs when there is a difference in the amount of phase change that the signal light receives or the loss of light, mainly between the two optical waveguides of the phase modulation unit. Signal distortion of output light.
- FIG. 7A shows a constellation map (Constellation Map) in the case where there is chirp distortion when there is no chirp distortion.
- Constellation Map Constellation Map
- the output light of the optical modulator linearly changes from the phase 0 to the state of phase 0 on the constellation map.
- the Si light modulator In the manufacturing process of the Si light modulator, in the implantation step of implanting p-type and n-type dopants into the Si layer, if an offset (offset) of the pn junction position due to a mask deviation or the like occurs, the light modulation characteristic Cause deterioration.
- misalignment of the pn junction position (for example, the vertical direction in FIG. 2 and the horizontal direction in FIG. 3) occurs due to such mask misalignment in the manufacturing process of the Mach-Zehnder modulator, doping with the two optical waveguides constituting the Mach-Zehnder modulator Due to the symmetry of the structure, for example, the p-type layer is large in one waveguide and the p-type layer is small in the other waveguide. This causes a difference in modulation efficiency between the two waveguides, and the multiplexed modulated optical signal has a chirp distortion.
- the accuracy of mask alignment at the time of device fabrication is about ⁇ 30 nm, and this kind of mask deviation can generally occur. Deviations of several tens of nm are difficult to measure, and it is difficult to guarantee the fabrication accuracy of ⁇ 50 nm or less by the usual manufacturing method.
- FIGS. 8A and 8B show the degradation of the optical signal quality due to such an implantation mask shift.
- FIG. 8A shows the entire constellation map of a degraded 64 QAM modulated signal
- FIG. 8B is a diagram for explaining the definition of the indicator FoD ( Figure of Deterioration) of degradation of signal quality in such a map.
- FIG. 9A shows a graph of the value of FoD when the position of the pn junction deviates from the set position by the offset amount (nm). Further, (b) of FIG. 9 shows a constellation map of the entire 64 QAM signal when shifted by 30 nm when shifted by 10 nm. As can be seen from (a) and (c) of FIG. 9, when the shift is 30 nm, 30% or more of the symbol interval is consumed due to the S-shape distortion of the constellation, and the signal quality is significantly degraded.
- Values (w / lin.) Indicated by black dots in the graph of FoD in (a) of FIG. 9 are values obtained as a result of performing correction processing with a linearizer that performs additional signal processing. It is shown that the correction processing is hardly effective as compared with the value before correction (white dot: wo / lin.) Because the deterioration of the signal quality is large.
- the present invention has been made in view of such a problem, and an object thereof is to provide an optical modulator having good waveform quality by suppressing chirp at the time of phase modulation due to a mask displacement or the like. .
- the present invention is characterized by having the following configuration in order to achieve such an object.
- Two RF electrodes for applying a pair of differential signal voltages, at least one fixed potential electrode for applying a fixed potential, and a first conductive semiconductor layer in contact with the RF electrode or the fixed potential electrode
- a second conductive type semiconductor layer and two optical waveguides disposed along a pn junction which is branched from one optical waveguide and becomes a boundary of the first and second conductive type semiconductor layers are formed.
- a light modulator comprising: a light modulator; The semiconductor layer and the electrode are disposed such that the integral of the phase change due to the position of the pn junction in the two optical waveguides being deviated from the design value is equal between the two optical waveguides.
- the modulation unit of the light modulator has a first area located on the input side in the light propagation direction and a second area located on the output side, At the connection between the first area and the second area, the RF electrode and the optical waveguide have a three-dimensional intersection, In both of the two optical waveguides, in the first region and the second region, the positional relationship of the doping state of the semiconductor is arranged to be opposite to the propagation direction of the light of the respective optical waveguides. about,
- Configuration 1 of the invention characterized by
- the first area is divided into two so as to sandwich the second area, and the ratio of the length in the light propagation direction is 1: 2: 1.
- the light modulator as described in 5.
- the invention is characterized in that the fixed potential electrode has a dual electrode structure including a ground electrode disposed between two RF electrodes and two ground electrodes disposed outside the two RF electrodes.
- the light modulator according to any one of Configurations 1 to 6.
- the displacement (offset amount) of the pn junction position due to the mask displacement at the time of implantation has equal influence on the modulation efficiency in the two waveguides constituting the Mach-Zehnder modulator.
- the attenuation with the propagation of the high-frequency electrical signal sets the length of the first area and the second area appropriately, while the efficiency that can cancel the difference in modulation efficiency differs between the input side and the output side of the RF electrode.
- FIG. 3 is a cross-sectional view of the Si light modulator of FIG. 2 taken along the line III-III.
- FIG. 3 is a doping state of a semiconductor in a cross section of the Si light modulator of FIG. 2 and a band diagram at the time of light modulation.
- FIG. 6 is a partial cross-sectional view of a VI-VI partial cross section of the Si light modulator of FIG.
- FIG. 7 is a diagram showing an entire constellation map of a degraded 64 QAM modulated signal. It is a figure explaining the definition of parameter
- FIG. 11 is a doping state of a semiconductor in the XIA-XIA section of FIG. 10 and a band diagram at the time of light modulation.
- FIG. 11 is a doping state of a semiconductor in the XIB-XIB cross section of FIG. 10 and a band diagram at the time of light modulation. It is a reference drawing of an optical modulator in case there is no crossing of RF electrode like a prior art.
- FIG. 13 is a doping state of a semiconductor in the XIIIA-XIIIA cross section of the reference diagram of FIG. 12 and a band diagram at the time of light modulation.
- FIG. 13 is a doping state of a semiconductor in the XIIIB-XIIIB cross section of the reference diagram of FIG.
- FIG. 15 is a view showing a doping state of a semiconductor in the XVA-XVA cross section of FIG. 14 and a band diagram at the time of light modulation.
- FIG. 15 is a view showing a doping state of a semiconductor in an XVB-XVB cross section of FIG. 14 and a band diagram at the time of light modulation.
- FIG. 15 is a view showing a doping state of the semiconductor in the XVC-XVC cross section of FIG. 14 and a band diagram at the time of light modulation.
- FIG. 17 is a view showing a doping state of a semiconductor in the XVIIA-XVIIA cross section of FIG. 16 and a band diagram at the time of light modulation.
- FIG. 17 is a view showing a doping state of a semiconductor in the XVIIB-XVIIB cross section of FIG. 16 and a band diagram at the time of light modulation. It is a top view which shows the structure of the Mach-Zehnder type
- FIG. 21 is a plan view showing a configuration of a dual electrode light modulator according to an eighth embodiment of the present invention. It is a top view which shows the structure of the optical modulator of the dual electrode structure of the modification of the 5th Embodiment of this invention.
- FIG. 10 is a plan view showing the configuration of a Mach-Zehnder type optical modulator with a single electrode structure according to the first embodiment of the present invention.
- the first region (the section surrounded by the alternate long and short dash line of the cross section XIA-XIA) whose modulation part is located on the input side of the light propagation direction of the optical waveguide
- the second region (portion enclosed by the dashed line in the cross section XIB-XIB) located on the output side.
- doping state of semiconductor is the same pattern arrangement and reverse (for example, n-type and n-type part for p-type part) Is doped to be p-type).
- the two upper and lower RF electrodes 5a and 5b for applying a pair of differential signal voltages are connected in a structure in which they are three-dimensionally intersected without being in contact with each other in the middle between the first and second regions. It is done.
- the RF electrode 5a is directly connected from the upper left to the lower right while the RF electrode 5b is once dropped to the lower layer of the RF electrode 5a with a via (through electrode). After connecting to the upper right, it is possible to connect to the upper layer by vias again.
- the RF electrode and the optical waveguide also cross each other.
- the optical waveguide and the RF electrode are originally formed in different layers, the optical waveguide by this intersection There is no influence on the manufacturing aspect of
- the DC electrodes 6a and 6b for applying a bias voltage between two RF electrodes have opposite doping states in the two regions, they need to have opposite bias voltage polarities. And an independent structure electrically isolated in the second region.
- the cross-sectional structure of the optical waveguide in the two regions is also schematically shown in the upper view of FIG. 11A and FIG. 11B, but basically, except that the doping state (conductivity type, polarity) is reversed.
- the structure is the same as that of FIG. That is, in the first region, both of the two RF electrodes 5a and 5b are in contact with the semiconductor layer of the first conductivity type (for example, p type), and the DC electrode 6a has the second conductivity type opposite to the first conductivity type (for example, p For the type, it is in contact with the n-type semiconductor layer.
- the two RF electrodes 5b and 5a after intersection both are in contact with the second conductivity type (n-type) semiconductor layer, and the DC electrode 6b is in contact with the first conductivity type (p-type) semiconductor layer ing.
- Si optical waveguides for propagating light are formed at two pn junctions which are boundaries between the first and second conductive type semiconductor layers, and they are Si light modulators having a single electrode structure.
- the two RF electrodes have a continuous structure electrically connected in the first region and the second region, respectively, and the DC electrode is electrically isolated in the first region and the second region.
- the two RF electrodes have a structure in which the first and second regions three-dimensionally cross each other without being in contact with each other.
- the ratio of the length to the total length of each region is set to about 1/2 in the light propagation direction.
- 11A and 11B show the doping state of the semiconductor in the XIA-XIA and XIB-XIB sections of FIG. 10 and a band diagram at the time of light modulation.
- the two RF electrodes are both in contact with the p-type semiconductor layer, and a differential signal is applied.
- the DC electrode is in contact with the n-type semiconductor layer, and a reverse voltage is applied to the pn junction by applying a positive voltage to the RF electrode.
- both of the two RF electrodes are in contact with the n-type semiconductor layer, and a differential signal is applied. Further, the DC electrode is in contact with the p-type semiconductor layer, and a reverse voltage is applied to the pn junction by applying a negative voltage to the RF electrode.
- the RF electrode is a continuous structure electrically connected in the first region and the second region, but since the first region and the second region cross three-dimensionally without being in contact with each other, XIA -In the XIA and XIB-XIB cross sections, the voltage application state is reversed from left to right. For this reason, even if the voltage applied to the DC electrode is reversed between plus and minus in the first region and the second region, the voltage in the first region is applied to the pn junction provided in the optical waveguide. Is large, the voltage is large even in the second region, and when the voltage is small in the first region, the voltage is small also in the second region.
- the carrier density in the two optical waveguides is changed, and the refractive index of each of the waveguides is changed to perform phase modulation of light to cause the light to interfere. It is necessary to make the phase change in the same direction in the whole area.
- the displacement (offset amount) of the pn junction position due to the mask displacement at the time of implantation can be offset by plus and minus in the first region and the second region. That is, when the implantation mask is shifted to increase the number of p-type layers in the first region, the number of p-type layers is shifted in the second region formed by the same mask. As a result, the difference in modulation efficiency between the two waveguides constituting the Mach-Zehnder modulator is reduced, and an optical modulator with good signal quality can be realized.
- the ratio of the length to the total length of each region is approximately 1/2 in the light propagation direction.
- the absolute values are made equal while the change in the modulation characteristics is opposite in the first region and the second region. Therefore, it is necessary to make the lengths of the first region and the second region approximately equal, and the ratio of the length to the total length of each region is approximately 1 ⁇ 2.
- the length in the propagation direction of the light in the first region on the input side of the RF signal is output It needs to be shorter than the length of the second region on the side.
- the appropriate length ratio varies depending on the amount of attenuation of the RF electrode and the difference in contact resistance between the first and second regions and the semiconductor layer, but it will be approximately 1: 3 to about 1: 1. .
- the effect of offsetting the change in modulation characteristics due to the displacement of the pn junction position can also be confirmed in the range of the length ratio of 1: 5 to 5: 1.
- the RF electrode is in contact with the p-type semiconductor layer in the first region and the DC electrode is in contact with the n-type semiconductor layer.
- the RF electrode is n-type in the first region. Even if the DC electrode is in contact with the semiconductor layer and the DC electrode is in contact with the p-type semiconductor layer, the same effect can be obtained.
- the RF electrode is preferably a wiring using a metal with a low resistivity to prevent the attenuation of high frequency signals
- the DC electrode can be replaced by a wiring using the conductivity of the semiconductor layer instead of a metal.
- the DC electrode does not have to extend over the entire area of the first region or the second region, and may be in contact with only a part.
- FIG. 14 is a plan view showing the configuration of a Mach-Zehnder type optical modulator with a single electrode structure according to a second embodiment of the present invention.
- the first region is located on the input side of the light waveguide in the light propagation direction of the optical waveguide (cross section XVA-XVA, dashed line enclosed portion) And another first area (cross section XVC-XVC surrounded by a dashed dotted line), and a second area (cross section XVB-XVB surrounded by a dashed dotted line) located between the two first areas.
- the doping state of the semiconductor (the conductivity type of the semiconductor such as p-type and n-type) is reversed in the first and second regions, and two lines for applying a pair of differential signal voltages
- the RF electrodes are connected in two places between the first area and the second area on the input side and between the first area and the second area on the output side.
- a bias voltage is applied between the two RF electrodes.
- the two RF electrodes are in contact with the second conductivity type semiconductor layer, and the DC electrode is in contact with the first conductivity type semiconductor layer.
- Si optical waveguides for propagating light are formed at two pn junctions which are boundaries between the first and second conductivity type semiconductor layers, thus forming a Si light modulator of a single electrode structure.
- the two RF electrodes have a continuous structure electrically connected in the first region and the second region, respectively, and the DC electrode has an independent structure electrically separated in the first region and the second region.
- the two RF electrodes have a structure in which they are sterically intersected without being in contact with each other at two places between two first regions and second regions.
- the length ratio is set to, for example, about 1: 2: 1 in the light propagation direction.
- 15A, 15B, and 15C show the doping state of the semiconductor in the XVA-XVA, XVB-XVB, and XVC-XVC sections of FIG. 14 respectively, and a band diagram at the time of light modulation.
- the two RF electrodes are both in contact with the p-type semiconductor layer, and a differential signal is applied.
- the DC electrode is in contact with the n-type semiconductor layer, and a reverse voltage is applied to the pn junction by applying a positive voltage to the RF electrode.
- the two RF electrodes are both in contact with the n-type semiconductor layer, and a differential signal is applied. Further, the DC electrode is in contact with the p-type semiconductor layer, and a reverse voltage is applied to the pn junction by applying a negative voltage to the RF electrode.
- both of the two RF electrodes are in contact with the p-type semiconductor layer. A signal is being applied.
- the DC electrode is in contact with the n-type semiconductor layer, and a reverse voltage is applied to the pn junction by applying a positive voltage to the RF electrode.
- the RF electrode is a continuous structure electrically connected in the first region and the second region, but since the first region and the second region intersect three-dimensionally without being in contact with each other, XVA In the XVA cross section and the XVB-XVB cross section, the voltage application state is reversed from left to right. In addition, even in the XVB-XVB cross section and the XVC-XVC cross section, the voltage application state is reversed from right to left. In the pn junction provided in the optical waveguide shown in FIG. 14, when the voltage is large in the first region, the voltage is large in the second region, and the voltage is small in the first region. In the state, the voltage is small even in the second region.
- the carrier density in the two optical waveguides is changed, and the refractive index of each of the waveguides is changed to perform phase modulation of light to cause the light to interfere. It is necessary to make the phase change in the same direction in the whole area.
- the magnitude of the potential difference applied to the pn junction in the first region and the second region is reversed, and the difference in the phase change is canceled by the two optical waveguides in the entire region of the optical modulator. Therefore, it is necessary to have a structure in which the RF electrodes are crossed and the potential difference applied to the pn junction is in the same state over the entire optical waveguide.
- the shift (offset amount) of the pn junction position due to the mask shift at the time of implantation can be offset by plus and minus in the first region and the second region. That is, when the implantation mask is shifted to increase the number of p-type layers in the first region, the number of p-type layers is shifted in two second regions formed by the same mask. As a result, the difference in modulation efficiency between the two waveguides constituting the Mach-Zehnder modulator is reduced, and an optical modulator with good signal quality can be realized.
- the first and second regions have a length ratio of about 1: 2: 1 in the light propagation direction.
- the absolute values are made equal while the change in the modulation characteristics is opposite in the first region and the second region.
- the decrease in modulation efficiency due to the attenuation can also be offset by setting the length ratio to 1: 2: 1. This makes it easy to change the modulation characteristics due to the displacement of the pn junction position without measuring the attenuation of the RF electrode or the difference in contact resistance between the electrodes in the first and second regions and the semiconductor layer. Can be offset in the first and second regions.
- the RF electrode is in contact with the p-type semiconductor layer in the first region and the DC electrode is in contact with the n-type semiconductor layer, the RF electrode is n-type in the first region. Even if the DC electrode is in contact with the semiconductor layer and the DC electrode is in contact with the p-type semiconductor layer, the same effect can be obtained.
- the first region not only the first region but also the second region is divided, and the same effect can be obtained even if the first and second regions are alternately provided in a plurality of places in the light propagation direction.
- FIG. 16 is a plan view showing the configuration of a Mach-Zehnder optical modulator with a single electrode structure according to a third embodiment of the present invention.
- the RF electrodes have a cross structure as in the first embodiment, but the doping structure of the semiconductor is the same in the two regions, and instead, the optical waveguide is a cross structure. .
- the first region is located on the input side of the light waveguide in the light propagation direction of the optical waveguide (cross section XVIIA-XVIIA enclosed by an alternate long and short dash line) And the second region (cross section XVIIB-XVIIB enclosed by the alternate long and short dash line) located on the output side, and the doping state of the semiconductor (the conductivity type of the semiconductor such as p-type and n-type) is the same in the two regions, Two RF electrodes for applying a pair of differential signal voltages, a three-dimensional cross connection between the first region and the second region, and a DC for applying a bias voltage between the two RF electrodes In the first region, the two RF electrodes are in contact with the p-type semiconductor layer in the first region, and the DC electrode is in contact with the n-type semiconductor layer doped with n-type which is doping different in polarity from the RF electrode .
- the two RF electrodes are both in contact with the p-type semiconductor layer, and the DC electrode is in contact with the n-type semiconductor layer doped with n-type which is doping different in polarity from the RF electrode.
- a Si optical waveguide for propagating light is formed at two pn junctions, which is a boundary between the p-type semiconductor layer and the n-type semiconductor layer, and it is a Si optical modulator of a single electrode structure.
- the two RF electrodes have a continuous structure electrically connected in the first region and the second region, respectively, and the DC electrode is a continuous structure electrically connected in the first region and the second region, or It has an independent structure which is electrically separated, and two RF electrodes have a structure which three-dimensionally intersects without contacting each other between the first region and the second region, and two Si optical waveguides. Has an intersecting structure between the first area and the second area.
- the ratio of the length to the total length of each region is set to, for example, about 1/2 in the light propagation direction.
- 17A and 17B show the doping state of the semiconductor and the band diagram at the time of light modulation in the XVIIA-XVIIA and XVIIB-XVIIB cross sections of FIG.
- the two RF electrodes are both in contact with the p-type semiconductor layer, and a differential signal is applied.
- the DC electrode is in contact with the n-type semiconductor layer, and a reverse voltage is applied to the pn junction by applying a positive voltage to the RF electrode.
- the two RF electrodes are both in contact with the p-type semiconductor layer, and a differential signal is applied.
- the DC electrode is in contact with the n-type semiconductor layer, and a reverse voltage is applied to the pn junction by applying a positive voltage to the RF electrode.
- the RF electrodes have a continuous structure electrically connected to each other in the first region and the second region, but since they intersect in a three-dimensional manner without being in contact with each other between the first region and the second region, XVIIA In the XVIIA and XVIIB-XVIIB cross sections, the voltage application state is reversed from left to right.
- the Si optical waveguide also intersects the first region and the second region, the voltage application state received by the light propagating through the Si optical waveguide does not change in the XVIIA-XVIIA and XVIIB-XVIIB cross sections. Therefore, in the pn junction provided in the optical waveguide, when the voltage is large in the first region, the voltage is large in the second region, and the voltage is small in the first region. At the time, the voltage is small even in the second region.
- the carrier density in the two optical waveguides is changed, and the refractive index of each of the waveguides is changed to perform phase modulation of light to cause the light to interfere. It is necessary to make the phase change in the same direction in the whole area.
- the optical modulator of the first embodiment it is necessary to prepare two voltages, positive and negative, with respect to the RF electrode with respect to the RF electrode in the first region and the second region, but the optical modulator of the third embodiment
- the doping structure in the two regions is the same, so that the voltage applied to the DC electrode can be one.
- the bias voltage can be finely controlled with the same polarity in the first region and the second region by forming the DC electrode as an independent structure electrically separated in the first region and the second region.
- the shift (offset amount) of the pn junction position due to the mask shift at the time of implantation can be offset by plus and minus in the first region and the second region. That is, since the doping structures in the two regions are the same, and the two RF electrodes and the optical waveguide cross each other, for example, in the optical waveguide of one of the first regions (for example, the upper side of FIG. When the mold layer is shifted so as to increase, the light propagating through the optical waveguide is shifted so that the p-type layer is reduced due to the intersection of the optical waveguides in the second region formed by the same mask ( For example, the light guide in the lower side of FIG. As a result, the difference in modulation efficiency between the two waveguides constituting the Mach-Zehnder modulator is reduced, and an optical modulator with good signal quality can be realized.
- the ratio of the length to the total length of each region is approximately 1/2 in the light propagation direction.
- the absolute values are made equal while the change in the modulation characteristics is opposite in the first region and the second region. Therefore, it is necessary to make the lengths of the first region and the second region approximately equal, and the ratio of the length to the total length of each region is approximately 1 ⁇ 2.
- the length in the propagation direction of the light in the first region on the input side of the RF signal is output It needs to be shorter than the length of the second region on the side.
- the appropriate length ratio varies depending on the amount of attenuation of the RF electrode and the difference in contact resistance between the first and second regions and the semiconductor layer, but it will be approximately 1: 3 to about 1: 1. .
- the effect of offsetting the change in modulation characteristics due to the displacement of the pn junction position can also be confirmed in the range of the length ratio of 1: 5 to 5: 1.
- the RF electrode is in contact with the p-type semiconductor layer in the first region and the DC electrode is in contact with the n-type semiconductor layer.
- the RF electrode is n-type semiconductor The same effect can be obtained even if the DC electrode is in contact with the layer and the DC electrode is in contact with the p-type semiconductor layer.
- the RF electrode is preferably a wiring using a metal with a low resistivity to prevent the attenuation of high frequency signals
- the DC electrode can be replaced by a wiring using the conductivity of the semiconductor layer instead of a metal.
- the DC electrode does not have to extend over the entire area of the first region or the second region, and may be in contact with only a part.
- FIG. 18 is a plan view of a Mach-Zehnder type optical modulator having a single electrode structure as a fourth embodiment of the present invention.
- the fourth embodiment of FIG. 18 has the same basic structure as the first embodiment of FIG. 10, but in the first and second regions, the wiring for applying a voltage to the DC electrodes 6a and 6b is the RF electrode 5a. , 5b and has a structure that intersects sterically.
- the DC electrodes 6a and 6b in FIG. 18 have a structure in which they are three-dimensionally crossed without being in contact with the RF electrodes 5a and 5b in the wiring of the lead-out portion, and the electrodes are not electrically connected to each other. Since the DC electrode and the RF electrode intersect three-dimensionally, the bypass of the electrical wiring can be eliminated, and a small-sized optical modulator can be realized.
- the wiring of the lead-out portion is performed in this manner to the DC electrode.
- an optical modulator which can be easily fed and has no trouble in the wiring layout and the like when using the device.
- FIG. 19 (Description of the effect of the first embodiment)
- the state of the improvement of the deterioration of the optical signal quality when the position of the pn junction is shifted is defined by FIG. Indicated by FoD in a 64 QAM modulated signal.
- the change of the modulation characteristic due to the shift of the pn junction position is offset in the first region and the second region, so that it is possible to realize an optical modulator with good signal quality. For this reason, as shown in FIG. 19, even when a mask shift (offset amount) of 30 nm occurs at implantation, FoD is 5% or less, and 30% or more of the symbol interval is consumed by S-shape distortion of constellation. It is shown that a great improvement effect can be obtained compared to the prior art (FIG. 9A).
- FIG. 20 shows the transmission characteristics and the reflection characteristics of the RF signal of the optical modulator according to the first embodiment of the present invention as a result of being represented by S parameters.
- the light modulator according to the first embodiment has a structure in which the RF electrodes cross each other in three dimensions without being in contact with each other between the first region and the second region. In such a structure, it is feared that the reflection of the RF signal is increased, the transmitted signal is decreased, and the modulation efficiency is degraded. However, by designing the shape of the appropriate crossing, it is possible to maintain good characteristics with an increase of reflection of 1.5 dB or less and almost no transmission signal decrease.
- the crossing of the RF electrodes is realized using the multilayer wiring technology of the metal between the SiO 2 layers, which can be introduced in the usual manufacturing process of the Si light modulator.
- the wiring may be formed by wire bonding after the manufacturing of the Si light modulator.
- the two RF electrodes corresponding to the two arms of the Mach-Zehnder modulator originally formed on the same layer are three-dimensionally intersected for the mask offset cancellation. It needs to be structured.
- the third embodiment (FIG. 16), three-dimensional crossover is required for two optical waveguides.
- one of two RF electrodes or two optical waveguides originally in the same layer is connected to another layer for a two-dimensional crossing of the RF electrodes or between the optical waveguides. Needs, which tends to complicate the manufacturing process of the light modulator.
- such a three-dimensional crossing structure can be eliminated by utilizing ground electrodes located outside and in the center of the RF electrode.
- FIG. 21 is a plan view showing a configuration of a Mach-Zehnder type optical modulator of a dual electrode structure according to a fifth embodiment of the present invention.
- the optical modulator according to the fifth embodiment of the present invention has a dual electrode structure as its modulator, and is located on the input side of the optical waveguide in the light propagation direction (cross section XXIIA- It is divided into XXIIA dashed-dotted line enclosed part, see also partial cross-sectional view in FIG. 22A), and a second region located on the output side (see dashed-dotted line enclosed part in cross section XXIIB-XXIIB, see partial cross-sectional view in FIG. 22B) ing.
- the Mach-Zehnder type optical modulator when looking at the upper arm of the Mach-Zehnder type optical modulator corresponding to the optical waveguide 7a of FIG. 21, for example, the first region on the left (section XXIIA-XXIIA In FIG. 22A), the optical waveguide 7a and the corresponding semiconductor region are disposed between the RF electrode 15a and the ground electrode 16a on the outer side, and in the second region on the right side (cross section XXIIB-XXIIB is FIG. 22B) , And between the RF electrode 15a and the central ground electrode 16c.
- the RF electrode 15a has a linear structure
- the optical waveguide 7a parallel to this is advanced in the light propagation direction and right-turned at the connection portion between the first region and the second region. After crossing under 15a, it has a so-called crank shape that turns left.
- the RF electrode 15b has a linear structure
- the optical waveguide 7b parallel to this goes ahead in the light propagation direction at the connection portion between the first area and the second area, and turns under the RF electrode 15b. After crossing, it has a crank shape that turns to the right.
- connection between the first region and the second region has a structure in which the RF electrode and the optical waveguide intersect with each other, but the RF electrode and the optical waveguide have different layer structures. There is no difficulty in making it.
- the positional relationship of the optical waveguide with respect to one RF electrode in the first region and the second region in the plane of FIG. 21 and the doping state of the semiconductor are And the entire structure of the first region and the second region including the two RF electrodes and the optical waveguide, which is disposed so as to be rotationally symmetrical 180 degrees around the intersection of the RF electrode and the optical waveguide, It is disposed so as to be mirror-symmetrical on the upper and lower sides of FIG. 21 with respect to the central ground electrode 16c.
- the two optical waveguides 7a and 7b constituting the Mach-Zehnder type optical modulator are interrupted in a crank shape from one side of the linear RF electrode to the other side in the middle of the first and second regions on the left and right. They are connected in a transition structure, and have a structure in which the RF electrodes and the optical waveguides intersect in a three-dimensional manner, but there is no three-dimensional intersection between the optical waveguides and the RF electrodes.
- one or more vias 4 are provided for electrical connection between the RF electrode and the semiconductor layer.
- the via 4 (through electrode) connecting the RF electrode 15a to the semiconductor layer 214 is temporarily disconnected at the connection portion (intersection portion with the optical waveguide) of the first region and the second region.
- the optical waveguide 7a (7b) sandwiches the crossing region in which the lower part of the RF electrode 15a transits from the upper left to the lower right (lower left to upper right) in FIG. It takes the structure that layers 214 are connected. With such a structure, the via and the optical waveguide are close to each other to prevent light from being absorbed by the metal and being lost.
- the ratio of the length to the total length of each region is set to about 1/2 in the light propagation direction.
- the central ground electrode 16c of the dual electrode structure including the sixth and seventh embodiments described below is shown as an integral electrode, in order to avoid the interference of the RF signal between the upper and lower arms and the crosstalk, the ground The electrode 16c can also be configured as a two-electrode structure (see Example 8 to be described later and 16c1 and 16c2 in FIG. 27 described later) divided in two up and down with the center line interposed therebetween.
- FIG. 21 an example is shown in which mirror symmetry is provided in the upper and lower portions of FIG. 21 with respect to the central ground electrode 16 c.
- the positional relationship of the optical waveguide with respect to the RF electrode, and the doping state of the semiconductor are such that they are 180 ° rotationally symmetric about the intersection of the RF electrode and the optical waveguide.
- the entire structure of the first region and the second region including the two RF electrodes and the optical waveguide may be disposed so as to be mirror-symmetrical to the central ground electrode 16c. You do not have to.
- the entire structure is translated from one arm to the other, as shown in FIG. It may be arranged as shown.
- the offset (offset amount) of the pn junction position due to the mask offset at the time of implantation can be offset by plus and minus in the first region and the second region. That is, when the implantation mask is shifted to increase the number of p-type layers in the first region, the number of p-type layers is shifted in the second region formed by the same mask. As a result, the difference in modulation efficiency between the two optical waveguides constituting the Mach-Zehnder modulator is reduced, and an optical modulator with good signal quality can be realized.
- the ratio of the length to the total length of each region is approximately 1/2 in the light propagation direction.
- the absolute values are made equal while the change in the modulation characteristics is opposite in the first region and the second region. Therefore, it is necessary to make the lengths of the first region and the second region approximately equal, and the ratio of the length to the total length of each region is approximately 1 ⁇ 2.
- the length in the propagation direction of the light in the first region on the input side of the RF signal is output It needs to be shorter than the length of the second region on the side.
- the appropriate length ratio varies depending on the amount of attenuation of the RF electrode and the difference in contact resistance between the first and second regions and the semiconductor layer, but it will be approximately 1: 3 to about 1: 1. .
- the effect of offsetting the change in modulation characteristics due to the displacement of the pn junction position can also be confirmed in the range of the length ratio of 1: 5 to 5: 1.
- the RF electrode is in contact with the n-type semiconductor layer in the first region and the ground electrode is in contact with the p-type semiconductor layer, but the RF electrode is p-type in the first region. Even if the ground electrode is in contact with the semiconductor layer and the ground electrode is in contact with the n-type semiconductor layer, the same effect can be obtained.
- FIG. 23 is a plan view showing a configuration of a dual electrode structure Mach-Zehnder type optical modulator according to a sixth embodiment of the present invention.
- the modulator has a dual electrode structure, and the first region located on the input side of the optical waveguide in the propagation direction of light (section XXIIA- XXIIA dashed-dotted line portion, partial cross-sectional view is the same as FIG. 22A), and another first area located on the output side (cross-section XXIIA-XXIIA on output side dashed line-dotted portion, partial cross-sectional view is FIG. Similarly, it is divided into three regions of a second region (a portion surrounded by an alternate long and short dash line in section XXIIB-XXIIB, a partial cross-sectional view is similar to FIG. 22B) sandwiched between two first regions.
- the Mach-Zehnder type optical modulator for example, when looking at the upper arm of the Mach-Zehnder type optical modulator corresponding to the optical waveguide 7a of FIG. 7a and the corresponding semiconductor region are disposed between the RF electrode 15a and the outer ground electrode 16a, and in the central second region are disposed between the RF electrode 15a and the central ground electrode 16c, Furthermore, in the first region on the right side, it is disposed again between the RF electrode 15a and the outer ground electrode 16a.
- the RF electrode 15a has a linear structure
- the optical waveguide 7a has a so-called double crank shape.
- the RF electrode and the optical waveguide cross each other at the two connection portions between the two left and right first regions and the second region.
- the RF electrode and the optical waveguide There is no difficulty in making as it is a separate layer structure.
- the positional relationship of the optical waveguide with respect to one RF electrode and the doping state of the semiconductor are A first region and a second region disposed so as to be respectively 180 degrees in rotational symmetry partially around each of two crossing points of the RF electrode and the optical waveguide, and including the two RF electrodes and the optical waveguide;
- the entire structure of is arranged so as to be mirror-symmetrical up and down with respect to the central ground electrode 16c.
- the two optical waveguides 7a and 7b constituting the Mach-Zehnder type optical modulator are arranged from the one side to the other side of the linear shaped RF electrode in the middle between the two left and right first areas and the central second area.
- the crank shape is connected in a transition structure without interruption, and has a structure in which the RF electrode and the optical waveguide intersect three-dimensionally, but there is no three-dimensional intersection between the optical waveguide and the RF electrode.
- vias 4 (through electrodes) connected from the RF electrode 15a to the semiconductor layer 214 are interrupted at two connection parts between the two left and right first regions and the central second region in FIG. Then, the optical waveguide 7a (7b) is placed under the RF electrode 15a (15b), and in FIG. 23, the RF electrode is formed by the via 4 in the second area again with the crossing area transitioning from upper left to lower right (lower left to upper right).
- the structure is such that the semiconductor layer 214 is connected to the semiconductor layer 214. With such a structure, the via and the optical waveguide are close to each other to prevent light from being absorbed by the metal and being lost.
- the length ratio is set to, for example, about 1: 2: 1 in the light propagation direction.
- the offset (offset amount) of the pn junction position due to the mask offset at the time of implantation can be offset by plus and minus in the two left and right first regions and the center second region. That is, when the implantation mask is shifted to increase the number of p-type layers in the first region, the number of p-type layers is shifted in the second region formed by the same mask. As a result, the difference in modulation efficiency between the two waveguides constituting the Mach-Zehnder modulator is reduced, and an optical modulator with good signal quality can be realized.
- the ratio of the length of the two left and right first regions and the central second region is approximately 1: 2: 1 in the light propagation direction.
- the absolute values are made equal while the change in the modulation characteristics is opposite in the first region and the second region. Since the high frequency signal is attenuated when propagating through the RF electrode, the decrease in modulation efficiency due to the attenuation can also be offset by setting the length ratio to 1: 2: 1.
- the RF electrode is in contact with the p-type semiconductor layer in the first region and the DC electrode is in contact with the n-type semiconductor layer, but the RF electrode is n-type in the first region. Even if the DC electrode is in contact with the semiconductor layer and the DC electrode is in contact with the p-type semiconductor layer, the same effect can be obtained.
- the first region not only the first region but also the second region is divided, and the same effect can be obtained even if the first and second regions are alternately provided in a plurality of places in the light propagation direction.
- FIG. 24 is a plan view showing a configuration of a Mach-Zehnder type optical modulator with a dual electrode structure according to a seventh embodiment of the present invention.
- the modulator has a dual electrode structure, and the first region located on the input side of the light propagation direction of the optical waveguide (section XXIIA- It is divided into the XXIIA dashed-dotted line enclosed part, the partial cross-sectional view is the same as Fig. 22A, and the second region located on the output side (cross-sectioned XXIIB-XXIIB dashed-dotted line part, the partial cross-sectional view is similar to Fig. 22B) ing.
- the optical waveguides 7a and 7b and the corresponding two semiconductor regions transit from the first region to the second region. It is arranged in a straight line without doing.
- the two RF electrodes 15a and 15b and the outer ground electrodes 16a and 16b are connected in transition from the first area to the second area, and are spaced apart from each other.
- the central ground electrode 16c is also formed wider in the second region on the right side than in the first region on the left side.
- the optical waveguide 7a and the corresponding semiconductor region are disposed on a straight line from the first region to the second region, in the first region on the left side, between the RF electrode 15a and the outer ground electrode 16a In the second region on the right side, it is arranged between the RF electrode 15a and the central ground electrode 16c.
- the optical waveguide 7a has a linear structure, but the RF electrode and the ground electrode on the outer side have a so-called crank shape.
- the connection between the first region and the second region has a structure in which the RF electrode and the optical waveguide intersect with each other, but the RF electrode and the optical waveguide have different layer structures. There is no difficulty in making it.
- the positional relationship of the optical waveguide with respect to one RF electrode in each region and the doping state of the semiconductor is arranged so as to be 180 degrees rotational symmetric about the intersection of the RF electrode and the optical waveguide, and in the first region and the second region including the two RF electrodes and the optical waveguide.
- the entire structure is arranged so as to be mirror-symmetrical up and down with respect to the central ground electrode 16c.
- the structure is such that the RF electrodes and the optical waveguides intersect in a three-dimensional manner, but the optical waveguides do not cross each other and the RF electrodes do not cross each other.
- vias 4 through electrodes
- the vias 4 (through electrodes) connected to are temporarily disconnected.
- the RF electrode 15a (15b) transitioning from the lower left to the upper right (upper left to lower right) in FIG. 24 over the optical waveguide 7a (7b) the RF electrode 15a is again formed by the via 4 in the second region.
- the semiconductor layer 214 are connected.
- the ratio of the length to the total length of each region is set to about 1/2 in the light propagation direction.
- the structure of bending the RF transmission line can offset the displacement of the pn junction position due to the mask displacement at the time of implantation. It is possible to realize an optical modulator with a good signal quality, with a small difference in modulation efficiency between the two waveguides constituting the device.
- FIG. 25 (Description of the effect of the fifth embodiment)
- the state of the improvement of the deterioration of the optical signal quality when the position of the pn junction shifts is defined by FIG. Indicated by FoD in a 64 QAM modulated signal.
- the change of the modulation characteristic due to the displacement of the pn junction position is offset in the first region and the second region, so that it is possible to realize an optical modulator with good signal quality.
- FoD becomes 5% or less, as in the case of the single electrode structure of Example 1 shown in FIG. It is shown that a large improvement effect can be obtained as compared with the prior art ((a) of FIG. 9) in which 30% or more of the symbol interval is consumed by the S-shape distortion of the constellation.
- FIG. 26 shows the transmission characteristics and the reflection characteristics of the RF signal of the optical modulator according to the fifth embodiment of the present invention as S parameters.
- the optical modulator according to the fifth embodiment has a dual electrode structure, and thus has a structure in which the RF electrode intersects the optical waveguide between the first region and the second region.
- an appropriate shape that does not prevent the propagation of the RF signal it is possible to maintain good characteristics with almost no increase in reflection and no attenuation of the transmission signal compared to the prior art. There is.
- the embodiments of the present invention have been described above in the case of the single electrode (Examples 1 to 4) and the dual electrode (Examples 5 to 7).
- the basic idea of the present invention common to these embodiments is the design value of the position of the pn junction of the semiconductor region in the optical waveguide in the optical waveguide of the two arms constituting the Mach-Zehnder type optical modulator.
- the semiconductor layer and the waveguide are arranged such that the integral of the phase change due to the shift is equal between the optical waveguides modulated by the two RF electrodes, thereby preventing the deterioration of the signal quality due to the mask shift and the like. It is on the point.
- the upper and lower arms are distinguished by suffixes a and b, and the distance of the optical transmission path measured from the input side of the phase modulation unit of each arm is x.
- the doping state of the semiconductor region of both arms is mirror symmetry / rotational symmetry or divided into a plurality of regions.
- the positional relationship of the optical waveguide with respect to the RF electrode and that the doping state of the semiconductor is uniform and constant, in order to prevent signal degradation more precisely. Is desirable.
- FIG. 27 is a plan view showing the configuration of a dual electrode structure Mach-Zehnder type optical modulator according to the eighth embodiment of the present invention.
- ground electrodes (16a and 16c1, 16b and 16c2) are disposed above and below the RF electrodes 15a and 15b, respectively.
- the doping state of the semiconductor region is arranged in the same order in the upper and lower sides of the two optical waveguides.
- pn may be reversed in the two optical waveguides in the same order.
- the optical waveguide may be arranged between the RF electrode and the lower ground electrode (16c1 or 16b).
- ground electrodes (16c1, 16c2) are present in FIG. 27 as being sandwiched between two RF electrodes, the lower side is in contact with the first conductivity type (for example, p-type) semiconductor layer, Since the upper side is close to the second conductivity type (for example, n-type) semiconductor layer, it is necessary to divide it into two because one will be affected by the upper and lower RF electrodes.
- first conductivity type for example, p-type
- the second conductivity type for example, n-type
- the modulator of the optical modulator has the first area located on the input side in the light propagation direction and the second area located on the output side.
- the RF electrode and the optical waveguide cross each other at the connection between the first area and the second area, the phase change due to the mask shift can be canceled and canceled for each arm.
- the optical modulator according to the present invention in any of the single electrode structure and the dual electrode structure, it is possible to offset the phase change due to the shift (offset amount) of the pn junction position due to the mask shift at implantation. Therefore, the difference between the modulation efficiencies of the two waveguides constituting the Mach-Zehnder modulator is small, and an optical modulator with good signal quality can be realized.
- the attenuation with the propagation of the high-frequency electrical signal sets the length of the first area and the second area appropriately, while the efficiency that can cancel the difference in modulation efficiency differs between the input side and the output side of the RF electrode. By doing this, it is also possible to realize an optical modulator with good symmetry of modulation efficiency.
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Abstract
Description
図2に、従来のシングル電極型のマッハツェンダ変調器であるSi光変調器の平面図を、図3にそのIII-III断面構造図を示す。(例えば非特許文献2参照)
図5には、従来のデュアル電極型のマッハツェンダ変調器を構成するSi光変調器の平面図を、図6には図5のVI-VI部分断面構造図を示す。
1対の差動信号電圧を印加するための2本のRF電極と、固定電位を与える少なくとも1本の固定電位用電極と、前記RF電極若しくは固定電位用電極と接する第1導電型半導体層と第2導電型半導体層と、1本の光導波路から分岐されて前記第1および第2導電型半導体層の境界となるpn接合部に沿うように配置された2本の光導波路が形成された光変調部とを備えた光変調器であって、
前記2本の光導波路における前記pn接合部の位置が設計値からずれることによる位相変化の積分量が2本の光導波路の間で等しくなるように前記半導体層と電極が配置されている
ことを特徴とする光変調器。
前記光変調器の変調部は、前記2本の光導波路において、半導体のドーピング状態の位置関係がそれぞれの光導波路に対して一致していること、
を特徴とする発明の構成1に記載の光変調器。
前記光変調器の変調部は、光の伝播方向の入力側に位置する第1領域と出力側に位置する第2領域とを有し、
第1領域と第2領域の接続部で、RF電極と光導波路が立体交差する構造を持ち、
前記2本の光導波路のどちらも、前記第1領域と第2領域で、半導体のドーピング状態の位置関係は、それぞれの光導波路の光の伝播方向に対して逆となるように配置されていること、
を特徴とする発明の構成1に記載の光変調器。
前記第1領域の光の伝播方向についての全長が、前記第2領域の光の伝播方向についての全長よりも短いこと
を特徴とする発明の構成3に記載の光変調器。
前記第1領域と前記第2領域のうち少なくとも一方が光の伝播方向について2つ以上に分割されて交互に配置されること
を特徴とする発明の構成3に記載の光変調器。
前記第1領域は前記第2領域を挟むように2つに分割されており、その光の伝播方向についての長さの比が1:2:1になっていること
を特徴とする発明の構成5に記載の光変調器。
前記固定電位用電極は2本のRF電極の間に配置されたDC電極からなるシングル電極構造であること
を特徴とする発明の構成1から6のいずれか1項に記載の光変調器。
前記固定電位用電極は2本のRF電極の間に配置されたグラウンド電極および2本のRF電極の外側に配置された2本のグラウンド電極からなるデュアル電極構造であること
を特徴とする発明の構成1から6のいずれか1項に記載の光変調器。
まず、シングル電極構造のマッハツェンダ変調器の実施形態を、いくつかの好適例を用いて詳細に説明する。
図10は、本発明の第1の実施形態による、シングル電極構造のマッハツェンダ型光変調器の構成を示す平面図である。
ここで、本発明の素子作製時にインプラを行う際の、インプラマスクずれによる特性劣化の防止効果について述べる。
図14は、本発明の第2の実施形態によるシングル電極構造のマッハツェンダ型光変調器の構成を示す平面図である。
2本のRF電極は2つの第1領域と第2領域の間の2箇所で、互いに接することなく立体的に交差する構造を持っている。ここで、第1および第2領域は、光の伝播方向について、長さの割合が例えばおおむね1:2:1に設定されている。
ここで、本発明の素子作製時にインプラを行う際の、インプラマスクずれによる特性劣化の防止効果について述べる。
これによって、RF電極の減衰量や、第1領域と第2領域の電極と半導体層との間のコンタクト抵抗の差などを測定しなくても容易に、pn接合位置のずれによる変調特性の変化を、第1領域と第2領域で相殺することができる。
図16は、本発明の第3の実施形態によるシングル電極構造のマッハツェンダ型光変調器の構成を示す平面図である。本実施例3では、実施例1と同様にRF電極は交差構造としているが、2つの領域で半導体のドーピング構造は同じとされており、代わりに光導波路を交差構造としたことを特徴とする。
ここで、素子作製時にインプラを行う際の、インプラマスクずれによる特性劣化の防止について述べる。
図18に本発明の第4の実施形態として、シングル電極構造のマッハツェンダ型光変調器の平面図を示す。図18の実施例4は、図10の実施例1と基本構造は同じであるが、第1領域および第2領域において、DC電極6a、6bに電圧を印加するための配線が、RF電極5a、5bと立体的に交差する構造を持つ。
図19には、本発明の実施例1(図10)のシングル電極構造の光変調器において、pn接合の位置がずれた際の光信号品質の劣化の改善の様子を、図8Bで定義した64QAMの変調信号でのFoDで示す。
上述したシングル電極構造のマッハツェンダ変調器の実施例1~4においては、従来技術に関連して述べたように、バイアスティなどの外部回路を簡単化できるというメリットがあるが、図3および各実施形態1~4の平面図から明らかなように、もともと同じ層上に構成されたマッハツェンダ変調器の2つのアームに対応する2本のRF電極どうしを、マスクずれ相殺のために立体的に交差した構造とする必要がある。実施形態3(図16)においては、2本の光導波路についても立体交差が必要となる。
図21は、本発明の第5の実施形態による、デュアル電極構造のマッハツェンダ型光変調器の構成を示す平面図である。
ここで、本発明の素子作製時にインプラを行う際の、インプラマスクずれによる特性劣化の防止効果について述べる。
pn接合位置のずれによる変調特性の変化を相殺する効果は、長さの比率が1:5から5:1の範囲でも確認することができる。
図23は、本発明の第6の実施形態による、デュアル電極構造のマッハツェンダ型光変調器の構成を示す平面図である。
ここで、本発明の素子作製時にインプラを行う際の、インプラマスクずれによる特性劣化の防止効果について述べる。
図24は、本発明の第7の実施形態による、デュアル電極構造のマッハツェンダ型光変調器の構成を示す平面図である。
実施例7においても、インプラマスクずれによる特性劣化の防止については、実施例5と同様な効果が得られることは明らかであるので説明は省略する。
図25には、本発明の実施例5(図21)のデュアル電極構造の光変調器において、pn接合の位置がずれた際の光信号品質の劣化の改善の様子を、図8Bで定義した64QAMの変調信号でのFoDで示す。
以上、本発明の実施例について、シングル電極(実施例1~4)とデュアル電極(実施例5~7)の場合を述べた。これらの各実施例に共通する本願発明の基本的な考え方は、マッハツェンダ型の光変調器を構成する2本のアームの光導波路において、光導波路における半導体領域のpn接合部の位置の設計値からのずれによる位相変化の積分量が、2本のRF電極で変調される光導波路の間で等しくなるように半導体層と導波路が配置されて、マスクずれなどによる信号品質の劣化を防いでいる点にある。
∫fa(x)dx=∫fb(x)dx (1)
が成立することが、合波後の光変調器出力のマスクずれによる信号品質の劣化を防ぐための基本となる条件である。
図27は、本発明の第8の実施形態による、デュアル電極構造のマッハツェンダ型光変調器の構成を示す平面図である。
∫fa(x)dx=∫fb(x)dx=定数 (2)
が成立することを意味する。
∫fa(x)dx=∫fb(x)dx=0 (3)
が成立することを意味する。
2 Si層
201 光導波路コア部分
202 スラブ領域
211 高濃度p型半導体層
212 中濃度p型半導体層
213 中濃度n型半導体層
214 高濃度n型半導体層
4 ビア(貫通電極)
5a、5b、15a、15b RF電極
6、6a、6b DC電極
7、7a、7b 光導波路
16a、16b、16c、16c1、16c2 グラウンド電極
Claims (8)
- 1対の差動信号電圧を印加するための2本のRF電極と、固定電位を与える少なくとも1本の固定電位用電極と、前記RF電極若しくは固定電位用電極と接する第1導電型半導体層と第2導電型半導体層と、1本の光導波路から分岐されて前記第1および第2導電型半導体層の境界となるpn接合部に沿うように配置された2本の光導波路が形成された光変調部とを備えた光変調器であって、
前記2本の光導波路における前記pn接合部の位置が設計値からずれることによる位相変化の積分量が2本の光導波路の間で等しくなるように前記半導体層と電極が配置されていること
を特徴とする光変調器。
- 前記光変調器の変調部は、前記2本の光導波路において、半導体のドーピング状態の位置関係がそれぞれの光導波路に対して一致していること、
を特徴とする請求項1に記載の光変調器。
- 前記光変調器の変調部は、光の伝播方向の入力側に位置する第1領域と出力側に位置する第2領域とを有し、
第1領域と第2領域の接続部で、RF電極と光導波路が立体交差する構造を持ち、
前記2本の光導波路のどちらも、前記第1領域と第2領域で、半導体のドーピング状態の位置関係は、それぞれの光導波路の光の伝播方向に対して逆となるように配置されていること、
を特徴とする請求項1に記載の光変調器。
- 前記第1領域の光の伝播方向についての全長が、前記第2領域の光の伝播方向についての全長よりも短いこと
を特徴とする請求項3に記載の光変調器。
- 前記第1領域と前記第2領域のうち少なくとも一方が光の伝播方向について2つ以上に分割されて交互に配置されること
を特徴とする請求項3に記載の光変調器。
- 前記第1領域は前記第2領域を挟むように2つに分割されており、その光の伝播方向についての長さの比が1:2:1になっていること
を特徴とする請求項5に記載の光変調器。
- 前記固定電位用電極は2本のRF電極の間に配置されたDC電極からなるシングル電極構造であること
を特徴とする請求項1から6のいずれか1項に記載の光変調器。
- 前記固定電位用電極は2本のRF電極の間に配置されたグラウンド電極および2本のRF電極の外側に配置された2本のグラウンド電極からなるデュアル電極構造であること
を特徴とする請求項1から6のいずれか1項に記載の光変調器。
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---|---|---|---|---|
JP2018205343A (ja) * | 2017-05-30 | 2018-12-27 | 日本電信電話株式会社 | 光送信機 |
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Families Citing this family (5)
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US10845670B2 (en) * | 2018-08-17 | 2020-11-24 | Taiwan Semiconductor Manufacturing Co., Ltd. | Folded waveguide phase shifters |
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US20220350179A1 (en) * | 2021-04-30 | 2022-11-03 | Marvell Asia Pte Ltd | Semiconductor-based optical modulator |
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013062096A1 (ja) * | 2011-10-26 | 2013-05-02 | 株式会社フジクラ | 光学素子及びマッハツェンダ型光導波路素子 |
US20140112611A1 (en) * | 2012-10-18 | 2014-04-24 | Acacia Communications Inc. | Robust modulator circuits using lateral doping junctions |
US20150043866A1 (en) * | 2013-08-09 | 2015-02-12 | Sifotonics Technologies Co., Ltd. | Electro-Optic Silicon Modulator With Capacitive Loading In Both Slots Of Coplanar Waveguides |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001174765A (ja) * | 1999-12-15 | 2001-06-29 | Ngk Insulators Ltd | 進行波形光変調器 |
US6836573B2 (en) | 2002-09-05 | 2004-12-28 | Fibest Kk | Directional coupler type optical modulator with traveling-wave electrode |
JP2004246219A (ja) | 2003-02-17 | 2004-09-02 | Yokogawa Electric Corp | 光変調器 |
US7257295B2 (en) * | 2004-09-20 | 2007-08-14 | Fujitsu Limited | Attachment-type optical coupler apparatuses |
JP2007133135A (ja) * | 2005-11-10 | 2007-05-31 | Ngk Insulators Ltd | 光導波路デバイス |
CN101960345B (zh) * | 2007-10-19 | 2013-01-02 | 光导束公司 | 用于模拟应用的硅基光调制器 |
US20130100090A1 (en) * | 2011-10-21 | 2013-04-25 | Qualcomm Mems Technologies, Inc. | Electromechanical systems variable capacitance device |
JP5590175B1 (ja) * | 2013-03-26 | 2014-09-17 | 住友大阪セメント株式会社 | 光変調器 |
-
2016
- 2016-08-03 JP JP2017532385A patent/JP6475838B2/ja active Active
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- 2016-08-03 SG SG11201800806WA patent/SG11201800806WA/en unknown
- 2016-08-03 US US15/744,208 patent/US10317709B2/en active Active
- 2016-08-03 EP EP16832526.4A patent/EP3333619B1/en active Active
- 2016-08-03 CN CN201680045508.0A patent/CN107924075B/zh active Active
- 2016-08-03 WO PCT/JP2016/003589 patent/WO2017022246A1/ja active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013062096A1 (ja) * | 2011-10-26 | 2013-05-02 | 株式会社フジクラ | 光学素子及びマッハツェンダ型光導波路素子 |
US20140112611A1 (en) * | 2012-10-18 | 2014-04-24 | Acacia Communications Inc. | Robust modulator circuits using lateral doping junctions |
US20150043866A1 (en) * | 2013-08-09 | 2015-02-12 | Sifotonics Technologies Co., Ltd. | Electro-Optic Silicon Modulator With Capacitive Loading In Both Slots Of Coplanar Waveguides |
Non-Patent Citations (2)
Title |
---|
THOMSON,DAVID J. ET AL.: "High Performance Mach- Zehnder-Based Silicon Optical Modulators", IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, 18 June 2013 (2013-06-18), XP011521722 * |
VERMEULEN,DIEDRIK ET AL.: "Demonstration of Silicon Photonics Push-Pull Modulators Designed for Manufacturability", IEEE PHOTONICS TECHNOLOGY LETTERS, vol. 28, no. 10, 24 February 2016 (2016-02-24), pages 1127 - 1129, XP011604650 * |
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JP2018205343A (ja) * | 2017-05-30 | 2018-12-27 | 日本電信電話株式会社 | 光送信機 |
JP2019056881A (ja) * | 2017-09-22 | 2019-04-11 | 住友電気工業株式会社 | マッハツェンダ変調器 |
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CA2994522C (en) | 2020-07-07 |
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CN107924075A (zh) | 2018-04-17 |
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