阅读说明：本技术 波导 (Waveguide ) 是由 C·鲍多特 S·盖尔贝 P·勒迈特瑞 于 2019-08-30 设计创作，主要内容包括：本公开的实施例涉及波导。在一个实施例中,波导包括上游部分、下游部分和上游部分和下游部分之间的中间部分。第一波带设置在绝缘层上,该第一波带沿第一方向定向。第一侧向条带和第二侧向条带,设置在第一波带的任一侧,该第一侧向条带和第二侧向条带沿中间部分变薄或者中断。(Embodiments of the present disclosure relate to waveguides. In one embodiment, the waveguide includes an upstream portion, a downstream portion, and an intermediate portion between the upstream portion and the downstream portion. A first band of waves is disposed on the insulating layer, the first band of waves being oriented in a first direction. First and second lateral bands disposed on either side of the first band, the first and second lateral bands being thinned or interrupted along a middle portion.)

1. A waveguide, comprising:

an upstream portion, a downstream portion, and an intermediate portion between the upstream portion and the downstream portion;

a first band of waves disposed on the insulating layer, the first band of waves oriented along a first direction; and

first and second lateral ribbons disposed on either side of the first ribbon, the first and second lateral ribbons thinning or being interrupted along the middle portion.

2. The waveguide of claim 1, wherein both the first lateral stripe and the second lateral stripe are in contact with the first waveband.

3. The waveguide of claim 2, wherein both the first and second lateral ribbons are in contact with respective lateral faces of the first ribbon.

4. The waveguide of claim 1, further comprising:

a second zone disposed adjacent to the first lateral band, wherein the first lateral band is disposed between the second zone and the first zone; and

a third zone disposed adjacent to the second lateral band, wherein the second lateral band is disposed between the third zone and the first zone.

5. The waveguide of claim 4, wherein the second and third wavebands are parallel to the first waveband.

6. The waveguide of claim 4, wherein the second and third wavebands include an absorbing material along the intermediate portion, the absorbing material configured to absorb wavelengths of signals intended to propagate through the waveguide.

7. The waveguide of claim 6, wherein the absorbing material is selected from the group consisting of: silicides, germanium, silicon carbide, germanium-silicon, tin, titanium nitride, tantalum nitride, tungsten, copper, and alloys or mixtures of these materials.

8. The waveguide of claim 1, wherein along the upstream and downstream portions, the first and second lateral strips are configured such that an effective optical index of a guided optical mode intended to propagate through the waveguide progressively changes up to the intermediate portion.

9. The waveguide of claim 1, wherein each of the first and second lateral strips is interrupted along the middle portion, and wherein the width of the first and second lateral strips progressively decreases along each of the upstream and downstream portions up to the middle portion.

10. The waveguide of claim 1, wherein each of the first and second lateral strips is thinned along the middle portion, and along each of the upstream and downstream portions, each of the first and second lateral strips includes an upper portion having a decreasing width up to the middle portion.

11. The waveguide of claim 1, wherein the intermediate portion is curved lengthwise.

12. The waveguide according to claim 1, wherein the insulating layer is a semiconductor-on-insulator type structure.

13. The waveguide of claim 1, wherein the first wavestrip, the first lateral stripe, and the second lateral stripe are all defined in a semiconductor layer of a semiconductor-on-insulator structure.

14. The waveguide of claim 1, wherein the first wavestrip, the first lateral stripe, and the second lateral stripe are each disposed on and in contact with the insulating layer of a semiconductor-on-insulator structure.

15. An integrated photonic circuit comprising at least one waveguide according to claim 1.

16. A method of filtering spurious modes of an optical signal, the method comprising:

an optical signal propagating through a waveguide, the waveguide comprising:

an upstream portion, a downstream portion, and an intermediate portion between the upstream portion and the downstream portion;

a first band of waves disposed on the insulating layer, the first band of waves oriented along a first direction; and

first and second lateral ribbons disposed on either side of the first ribbon, the first and second lateral ribbons thinning or being interrupted along the middle portion.

17. The method of claim 16, further comprising:

a second zone disposed adjacent to the first lateral band, wherein the first lateral band is disposed between the second zone and the first zone; and

a third zone disposed adjacent to the second lateral band, wherein the second lateral band is disposed between the third zone and the first zone.

18. The method of claim 17, wherein the second and third wavebands are parallel to the first waveband.

19. The method of claim 17, wherein the second and third bands of wavelengths include an absorbing material along the intermediate portion, the absorbing material configured to absorb wavelengths of signals intended to propagate through the waveguide.

20. The method of claim 16, wherein both the first lateral band and the second lateral band are in contact with respective lateral faces of the first zone.

21. The method of claim 16, wherein the first wavestrip, the first lateral stripe, and the second lateral stripe are all defined in a semiconductor layer of a semiconductor-on-insulator structure.

22. The method of claim 16, wherein the first ribbon, the first lateral stripe, and the second lateral stripe are each disposed on and in contact with the insulating layer of a semiconductor-on-insulator structure.

23. A waveguide, comprising:

a first upstream portion, a first downstream portion, and an intermediate portion between the first upstream portion and the first downstream portion;

a first band of waves disposed on the insulating layer, the first band of waves oriented along a first direction;

a second waveband disposed adjacent to the first waveband and on the insulating layer; and

a third wavelength band disposed adjacent to the first wavelength band and on the insulating layer, wherein the first wavelength band is disposed between the second wavelength band and the third wavelength band, wherein the second wavelength band and the third wavelength band include an absorbing material along the intermediate portion, the absorbing material configured to absorb wavelengths of signals intended to propagate through the waveguide.

24. The waveguide of claim 23, further comprising:

first and second lateral ribbons disposed on either side of the first ribbon, the first and second lateral ribbons being thinned or interrupted along the middle portion, wherein the first lateral ribbons are disposed between the second ribbon and the first ribbon, wherein the second lateral ribbons are disposed between the third ribbon and the first ribbon.

25. The waveguide of claim 24, wherein along the upstream and downstream portions, the first and second lateral strips are configured such that an effective optical index of a guided optical mode intended to propagate through the waveguide progressively changes up to the intermediate portion.

26. The waveguide of claim 24, wherein each of the first and second lateral strips is interrupted along the middle portion, and wherein the width of the first and second lateral strips progressively decreases along each of the upstream and downstream portions up to the middle portion.

27. The waveguide of claim 24, wherein each of the first and second lateral strips is thinned along the middle portion, and along each of the upstream and downstream portions, each of the first and second lateral strips includes an upper portion having a decreasing width up to the middle portion.

28. The waveguide of claim 23, wherein the intermediate portion is curved lengthwise.

29. The waveguide of claim 24, wherein both the first and second lateral ribbons are in contact with respective lateral faces of the first ribbon.

30. The waveguide of claim 24, wherein the first wavestrip, the first lateral stripe, and the second lateral stripe are all defined in a semiconductor layer of a semiconductor-on-insulator structure.

31. The waveguide of claim 24, wherein the first wavestrip, the first lateral stripe, and the second lateral stripe are each disposed on and in contact with the insulating layer of a semiconductor-on-insulator structure.

Technical Field

The present disclosure relates to the field of waveguides, and more particularly to waveguides for photonic (optoelectronic and/or optical) integrated circuits.

Background

In integrated photonic circuits, optical signals may be transmitted through waveguides. Currently, the dimensions of the cross-section of the waveguide are chosen such that a given optical mode of the signal, which is typically a transverse electric (TEo) and/or transverse magnetic (TMo) fundamental mode, is the only guided mode propagating through the waveguide. However, inhomogeneities in the waveguide material and/or variations in the waveguide geometry may lead to the occurrence of parasitic optical modes in the waveguide, i.e. higher order optical modes when the only guided mode is the fundamental mode. Such spurious modes are disturbing, in particular due to the fact that: harmful interference may occur between the guided mode and the spurious mode.

Disclosure of Invention

It is desirable to have a waveguide comprising a spurious mode filter device that overcomes at least some of the disadvantages of known spurious mode filter devices.

Drawings

The foregoing and other features and advantages will be discussed in detail in the following non-limiting description of specific embodiments, which is made in connection with the accompanying drawings.

FIG. 1 is a partial simplified top view of an embodiment of a waveguide;

FIG. 2 shows simplified cross-sectional views A, B and C of the waveguide of FIG. 1 along respective planes AA, BB and CC of FIG. 1; and

fig. 3 is a partial simplified top view of an alternative embodiment of the waveguide of fig. 1 and 2.

Embodiments provide a waveguide comprising a spurious mode filtering device, wherein the spurious mode filtering has a relatively limited, or even no, effect on the propagation of guided modes.

Accordingly, embodiments provide a waveguide comprising a first waveband and two lateral ribbons disposed on either side of the first waveband, the two ribbons thinning or breaking along a middle portion of the waveband.

According to one embodiment, the intermediate portion is a portion of the first zone length.

According to one embodiment, each zone is in contact with a first zone.

According to one embodiment, for each band, the second band and the first band are arranged on either side of the band.

According to one embodiment, each second zone extends parallel to the first zone.

According to one embodiment, each second wavelength band, along the intermediate portion, is made at least in part of a material selected to absorb wavelengths of signals intended to propagate through the waveguide.

According to one embodiment, the material is selected from the group comprising: silicides, germanium, silicon carbide, germanium-silicon, tin, titanium nitride, tantalum nitride, tungsten, copper, and alloys or mixtures of the foregoing.

According to one embodiment, the intermediate portion is interposed between two portions of the first zone.

According to one embodiment, along each of the two portions of the first waveband, the strip is configured such that the effective optical refractive index of a guided optical mode intended to propagate through the waveguide progressively varies up to the intermediate portion.

According to one embodiment, the bands are interrupted along a middle portion and the width of the band progressively decreases along each of the two portions of the first band, up to the middle portion.

According to one embodiment, the strips are thinned along the middle portion, and along each of the two portions of the first wave band, each strip comprises an upper portion which decreases in width up to the middle portion.

According to one embodiment, the intermediate portion is longitudinally curved.

According to one embodiment, the ribbons and strips are disposed on a silicon-on-insulator type insulating layer.

Another embodiment provides an integrated photonic circuit comprising at least one waveguide as described above.

Another embodiment provides a method of filtering spurious modes of an optical signal propagating through a waveguide as described above.