Optical waveguide interferometer with controllable length imbalance and minimum bend

Abstract

The invention relates to an optical waveguide interferometer with controllable length imbalance and minimum bend. The optical waveguide interferometer may include an input section, an intermediate section, and an output section, where the optical waveguide interferometer further includes a first arm portion having a first length spanning the input section, the intermediate section, and the output section, and a second arm portion having a second length spanning the input section, the intermediate section, and the output section, wherein a first length of the first arm portion is less than a second length of the second arm portion, and wherein the second arm portion has a curved shape.

Description

Technical Field

[0001] The disclosed subject matter relates generally to devices for fiber optic communications and, in some non-limiting embodiments, to the design of optical waveguide interferometers with controllable length imbalance and minimal bends. Background Art

[0002] Optical communication (e.g., optical telecommunications) may refer to a method of communicating between two locations at a distance by using light to carry information. An optical communication system may use a transmitter that encodes a message into an optical signal, a channel that carries the optical signal to its destination, and a receiver that reproduces the message from the optical signal received by the receiver.

[0003] Fiber optic communication may refer to a form of optical communication that involves transmitting information from one place to another by sending pulses of light (e.g., infrared light) through an optical fiber. Light may be used as a form of carrier wave that is modulated to carry information. Fiber optics may be preferable to cables in certain circumstances, such as when high bandwidth, long distances, and / or resistance to electromagnetic interference are required. Fiber optic communication can transmit voice, video, and telemetry data over a local area network or across long distances.

[0004] An interferometer may refer to a device that uses the interference of two light beams to provide information (e.g., in the form of a measurement result, a signal, etc.). In optical communications, an interferometer may be used as an electro-optical modulator for phase and / or amplitude modulation of light. In some cases, a delay line interferometer (DLI), which may include a Mach-Zehnder interferometer or a Michelson interferometer, may involve the use of a light beam that is delayed by a desired time interval compared to another light beam. The DLI may be referred to as an optical differential phase shift keying (DPSK) demodulator, so that the DLI can convert a phase keyed signal into an amplitude keyed signal. In such cases, the incoming DPSK optical signal may be divided into two equal intensity beams at the input of the two arms of the DLI. In this way, one beam is delayed by the optical path difference of the two arms, which may correspond to a 1-bit time delay. After the two equal intensity beams are combined at the output of the two arms of the DLI, the beams may interfere with each other constructively or destructively. The resulting interference intensity can be used as a signal carrying information, such as an intensity keying signal. Summary of the invention

[0005] It is therefore an object of the presently disclosed subject matter to provide an optical waveguide interferometer that overcomes some or all of the disadvantages of the prior art.

[0006] According to a non-limiting embodiment, an optical waveguide interferometer is provided, comprising: an input segment; an intermediate segment; an output segment; a first arm portion having a first length spanning the input segment, the intermediate segment, and the output segment; and a second arm portion having a second length spanning the input segment, the intermediate segment, and the output segment; wherein the first length of the first arm portion is less than the second length of the second arm portion; and wherein the second arm portion has a curved shape.

[0007] According to a non-limiting embodiment, an optical waveguide interferometer is provided, comprising: a first stage, the first stage comprising: a first input section; a first intermediate section; and a first output section; wherein the first stage further comprises: a first short arm portion spanning the first input section, the first intermediate section, and the first output section; and a first long arm portion spanning the first input section, the first intermediate section, and the first output section; wherein a span of the first short arm portion in the first intermediate section is shorter than a span of the first long arm portion in the first intermediate section; and wherein the first long arm portion has a first curved shape; a second stage, the second stage comprising: a second input section; a second intermediate section; and a second output section; wherein the second stage further comprises: a second short arm portion spanning the second input section, the second intermediate section, and the second output section; and a second long arm portion spanning the second input section, the second intermediate section, and the second output section; wherein a span of the second short arm portion in the second intermediate section is shorter than a span of the second long arm portion in the second intermediate section; wherein the second long arm portion has a second curved shape; and wherein the first output section of the first stage is coupled to the second input section of the second stage.

[0008] According to a non-limiting embodiment, an optical waveguide interferometer is provided, comprising: a first stage, the first stage comprising: a first input section; a first intermediate section; and a first output section; wherein the first stage further comprises: a first short arm portion spanning the first input section, the first intermediate section, and the first output section; and a first long arm portion spanning the first input section, the first intermediate section, and the first output section; wherein a span of the first short arm portion in the first intermediate section is shorter than a span of the first long arm portion in the first intermediate section; and wherein the first long arm portion has a first curved shape; a second stage, the second stage comprising: a second input section; a second intermediate section; and a second output section; wherein the second stage further comprises: a second short arm portion spanning the second input section, the second intermediate section, and the second output section; and a second long arm portion spanning the second input section, the second intermediate section, and the second output section; wherein a span of the second short arm portion in the second intermediate section is shorter than a span of the second long arm portion in the second intermediate section; wherein the second long arm portion has a second curved shape; wherein the first output section of the first stage is coupled to the second input section of the second stage; and wherein the first output section of the first stage is not parallel to the second input section of the second stage.

[0009] Other embodiments are set forth in the following numbered clauses:

[0010] Item 1: An optical waveguide interferometer comprising: an input segment; an intermediate segment; an output segment; a first arm portion having a first length spanning the input segment, the intermediate segment, and the output segment; and a second arm portion having a second length spanning the input segment, the intermediate segment, and the output segment; wherein the first length of the first arm portion is less than the second length of the second arm portion; and wherein the second arm portion has a curved shape.

[0011] Item 2: An optical waveguide interferometer according to Item 1, wherein the first arm portion has a first bend located at the transition of the first arm portion between the input section and the intermediate section; and wherein the second arm portion has a second bend located at the transition of the second arm portion between the input section and the intermediate section.

[0012] Item 3: An optical waveguide interferometer according to Item 1 or 2, wherein the first arm portion has a third bend located at the transition of the first arm portion between the middle section and the output section; and wherein the second arm portion has a fourth bend located at the transition of the second arm portion between the middle section and the output section.

[0013] Clause 4: An optical waveguide interferometer according to any one of clauses 1-3, wherein the first angle is defined by the first arm portion after a first bend and the second arm portion after a second bend, the first bend being located at a transition of the first arm portion between an input section and an intermediate section, and the second bend being located at a transition of the second arm portion between an input section and an intermediate section; and wherein the second angle is defined by the first arm portion before a third bend and the second arm portion before a fourth bend, the third bend being located at a transition of the first arm portion between an intermediate section and an output section, and the fourth bend being located at a transition of the second arm portion between an intermediate section and an output section; and wherein the first angle and the second angle are equal.

[0014] Clause 5: An optical waveguide interferometer according to any one of clauses 1-4, wherein the first arm portion has a first bend located at the transition of the first arm portion between the input section and the middle section; and wherein the first arm portion extends in a straight line to a third bend located at the transition between the middle section and the output section.

[0015] Clause 6: An optical waveguide interferometer according to any one of clauses 1-5, wherein the first arm portion at the input section is parallel to the second arm portion at the input section.

[0016] Clause 7: An optical waveguide interferometer according to any one of clauses 1-6, wherein the first arm portion at the output section is parallel to the second arm portion at the output section.

[0017] Clause 8: An optical waveguide interferometer according to any one of clauses 1-7, wherein the first arm portion has a first bend located at the transition of the first arm portion between the input section and the middle section; wherein the second arm portion has a second bend located at the transition of the second arm portion between the input section and the middle section; and wherein the first arm portion located before the first bend in the input section is parallel to the second arm portion located before the second bend in the input section.

[0018] Item 9: An optical waveguide interferometer according to any one of Items 1-8, wherein the first arm portion has a third bend located at the transition of the first arm portion between the middle section and the output section; wherein the second arm portion has a fourth bend located at the transition of the second arm portion between the middle section and the output section; and wherein the first arm portion located after the third bend in the output section is parallel to the second arm portion located after the fourth bend in the output section.

[0019] Clause 10: An optical waveguide interferometer according to any one of clauses 1-9, wherein the span of the first arm portion in the middle section has a width different from the width of the span of the second arm portion in the middle section.

[0020] Clause 11: An optical waveguide interferometer according to any one of clauses 1-10, wherein a first span of the first arm portion in the middle section has a width that is different from a width of a second span of the first arm portion in the middle section.

[0021] Clause 12: An optical waveguide interferometer according to any one of clauses 1-11, wherein a first span of the second arm portion in the middle section has a width that is different from a width of a second span of the second arm portion in the middle section.

[0022] Clause 13: An optical waveguide interferometer according to any one of clauses 1-12, wherein the input segment is a first input segment of a first stage, wherein the intermediate segment is a first intermediate segment of the first stage, and wherein the output segment is a first output segment of the first stage, and the optical waveguide interferometer further comprises: a second stage, wherein the second stage comprises: a second input segment; a second intermediate segment; a second output segment; and wherein the first output segment of the first stage is coupled to the second input segment of the second stage.

[0023] Item 14: An optical waveguide interferometer, comprising: a first stage, the first stage comprising: a first input segment; a first intermediate segment; and a first output segment; wherein the first stage further comprises: a first short arm portion spanning the first input segment, the first intermediate segment, and the first output segment; and a first long arm portion spanning the first input segment, the first intermediate segment, and the first output segment; wherein a span of the first short arm portion in the first intermediate segment is shorter than a span of the first long arm portion in the first intermediate segment; and wherein the first long arm portion has a first curved shape; a second stage, the second stage comprising: a second input segment; a second intermediate segment; and a second output segment; wherein the second stage further comprises: a second short arm portion spanning the second input segment, the second intermediate segment, and the second output segment; and a second long arm portion spanning the second input segment, the second intermediate segment, and the second output segment; wherein a span of the second short arm portion in the second intermediate segment is shorter than a span of the second long arm portion in the second intermediate segment; wherein the second long arm portion has a second curved shape; and wherein the first output segment of the first stage is coupled to the second input segment of the second stage.

[0024] Item 15: An optical waveguide interferometer according to Item 14, wherein the first short arm portion has a first bend located at a transition between the first input section and the first middle section of the first short arm portion; wherein the first long arm portion has a second bend located at a transition between the first input section and the first middle section of the first long arm portion; wherein the first short arm portion has a third bend located at a transition between the first short arm portion and the first output section; wherein the first long arm portion has a fourth bend located at a transition between the first middle section and the first output section of the first long arm portion; wherein the first angle is defined by the first short arm portion after the first bend and the first long arm portion after the second bend; wherein the second angle is defined by the first short arm portion before the third bend and the first long arm portion before the fourth bend; wherein the first The angle and the second angle are equal; wherein the second short arm portion has a fifth bend located at the transition of the second short arm portion between the second input section and the second middle section; wherein the second long arm portion has a sixth bend located at the transition of the second long arm portion between the second input section and the second middle section; wherein the second short arm portion has a seventh bend located at the transition of the second short arm portion between the second middle section and the second output section; wherein the second long arm portion has an eighth bend located at the transition of the second long arm portion between the second middle section and the second output section; wherein the third angle is defined by the second short arm portion after the fifth bend and the second long arm portion after the sixth bend; wherein the fourth angle is defined by the second short arm portion before the seventh bend and the second long arm portion before the eighth bend; and wherein the third angle and the fourth angle are equal.

[0025] Item 16: An optical waveguide interferometer according to Item 14 or 15, wherein the first short arm portion has a first bend located at the transition of the first short arm portion between the first input section and the first intermediate section; wherein the first short arm portion extends in a straight line to a third bend located at the transition between the first intermediate section and the first output section; wherein the second short arm portion has a fifth bend located at the transition of the second short arm portion between the second input section and the second intermediate section; and wherein the second short arm portion extends in a straight line to a seventh bend located at the transition between the second intermediate section and the second output section.

[0026] Clause 17: An optical waveguide interferometer according to any one of clauses 14-16, wherein the span of the first short arm portion in the first middle section has a width different from the width of the span of the first long arm portion in the first middle section; and wherein the span of the second short arm portion in the second middle section has a width different from the width of the span of the second long arm portion in the second middle section.

[0027] Clause 18: An optical waveguide interferometer according to any one of clauses 14-17, wherein a first span of the first short arm portion in the first middle section has a width different from a width of a second span of the first short arm portion in the first middle section; and wherein a third span of the second short arm portion in the second middle section has a width different from a width of a fourth span of the second short arm portion in the second middle section.

[0028] Item 19: An optical waveguide interferometer according to any one of items 14-18, wherein a first span of the first long arm portion in the first middle section has a width different from a width of a second span of the first long arm portion in the first middle section; and wherein a third span of the second long arm portion in the second middle section has a width different from a width of a fourth span of the second long arm portion in the second middle section.

[0029] Item 20: An optical waveguide interferometer, comprising: a first stage, the first stage comprising: a first input segment; a first intermediate segment; and a first output segment; wherein the first stage further comprises: a first short arm portion spanning the first input segment, the first intermediate segment and the first output segment; and a first long arm portion spanning the first input segment, the first intermediate segment and the first output segment; wherein a span of the first short arm portion in the first intermediate segment is shorter than a span of the first long arm portion in the first intermediate segment; and wherein the first long arm portion has a first curved shape; a second stage, the second stage comprising: a second input segment; a second intermediate segment; and a second output segment; wherein the second stage further comprises: a second short arm portion spanning the second input segment, the second intermediate segment and the second output segment; and a second long arm portion spanning the second input segment, the second intermediate segment and the second output segment; wherein a span of the second short arm portion in the second intermediate segment is shorter than a span of the second long arm portion in the second intermediate segment; wherein the second long arm portion has a second curved shape; wherein the first output segment of the first stage is coupled to the second input segment of the second stage; and wherein the first output segment of the first stage is not parallel to the second input segment of the second stage.

[0030] These and other features and characteristics of the presently disclosed subject matter, as well as the methods of operation and function of the associated elements of the structure and the economy of combination and manufacture of the parts, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It should be expressly understood, however, that the drawings are for purposes of illustration and description only and are not intended as a definition of the limits of the disclosed subject matter. As used in the specification and claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Additional advantages and details of the disclosed subject matter are explained in more detail below with reference to exemplary embodiments illustrated in the accompanying drawings, in which:

[0032] Figure 1 is a diagram of a non-limiting embodiment of an optical waveguide interferometer;

[0033] Figure 2 is a diagram illustrating a curved shape of a second arm portion of a non-limiting embodiment of an optical waveguide interferometer;

[0034] Figure 3 is a diagram of a non-limiting embodiment of an optical waveguide interferometer having multiple stages;

[0035] Figure 4 is a diagram of another non-limiting embodiment of an optical waveguide interferometer having multiple stages;

[0036] Figure 5is a diagram of another non-limiting embodiment of an optical waveguide interferometer; and

[0037] Figure 6 is a diagram of a non-limiting embodiment of an optical waveguide interferometer having multiple stages. DETAILED DESCRIPTION

[0038] For purposes of the description below, the terms "end," "upper," "lower," "right," "left," "vertical," "horizontal," "top," "bottom," "lateral," "longitudinal," and their derivatives shall relate to the disclosed subject matter as oriented in the accompanying drawings. However, it should be understood that the disclosed subject matter may assume various alternative variations and step sequences unless expressly specified to the contrary. It should also be understood that the specific devices and processes illustrated in the drawings and described in the following specification are merely exemplary embodiments of the disclosed subject matter. Accordingly, unless otherwise indicated, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered limiting.

[0039] Any aspect, component, element, structure, action, step, function, instruction and / or the like used in this article should not be interpreted as critical or necessary unless explicitly described as such. In addition, "one" and "an" used in this article are intended to include one or more items, and can be used interchangeably with "one or more" and "at least one". In addition, the term "set" used in this article is intended to include one or more items (e.g., related items, unrelated items, a combination of related items and unrelated items, etc.), and can be used interchangeably with "one or more" or "at least one". In the case of only meaning one item, the term "one" or similar language is used. In addition, the terms "having", "having" or similar terms used in this article are intended to be open-ended terms. In addition, unless otherwise explicitly stated, the phrase "based on" is intended to mean "based at least in part on".

[0040] In some non-limiting embodiments, a series of 90 degree bends of an optical fiber (e.g., an optical fiber acting as a waveguide) may be used to define the arms of a delay line interferometer (DLI) to keep the number of bends in both arms of the DLI the same and with a specific length imbalance as desired. However, depending on the specific application, such as a DLI on a planar photonic integrated circuit, it may be important to have an overall compact size of the DLI, which may be determined based on a specific arm length and minimal overbending (e.g., minimum number of turns, turns without sharp bends, etc.) to allow for proper routing of optical signals. Any additional waveguides introduced in the arms of the DLI may increase the risk of obtaining a detuned response due to design and / or manufacturing variations.

[0041] According to a non-limiting embodiment of the present disclosure, an optical waveguide interferometer may include an input segment, an intermediate segment, and an output segment, wherein the optical waveguide interferometer further includes a first arm portion having a first length spanning the input segment, the intermediate segment, and the output segment, and a second arm portion having a second length spanning the input segment, the intermediate segment, and the output segment, wherein the first length of the first arm portion is less than the second length of the second arm portion, and wherein the second arm portion has a curved shape (e.g., a curved shape having a curvature less than 90 degrees).

[0042] In some non-limiting embodiments, the first arm portion may have a first bend located at the transition of the first arm portion between the input section and the middle section, and the second arm portion may have a second bend located at the transition of the second arm portion between the input section and the middle section. In some non-limiting embodiments, the first arm portion has a third bend located at the transition of the first arm portion between the middle section and the output section, and the second arm portion has a fourth bend located at the transition of the second arm portion between the middle section and the output section. In some non-limiting embodiments, the first angle is defined by the first arm portion after the first bend and the second arm portion after the second bend, the first bend being located at the transition of the first arm portion between the input section and the middle section, the second bend being located at the transition of the second arm portion between the input section and the middle section, and the second angle is defined by the first arm portion before the third bend and the second arm portion before the fourth bend, the third bend being located at the transition of the first arm portion between the middle section and the output section, and the fourth bend being located at the transition of the second arm portion between the middle section and the output section. In some non-limiting embodiments, the first angle and the second angle are equal.

[0043] In some non-limiting embodiments, the first arm portion has a first bend located at the transition of the first arm portion between the input section and the middle section, and the first arm portion extends in a straight line to a third bend located at the transition between the middle section and the output section. In some non-limiting embodiments, the first arm portion at the input section is parallel to the second arm portion at the input section. In some non-limiting embodiments, the first arm portion at the output section is parallel to the second arm portion at the output section. In some non-limiting embodiments, the first arm portion has a first bend located at the transition of the first arm portion between the input section and the middle section, the second arm portion has a second bend located at the transition of the second arm portion between the input section and the middle section, and the first arm portion of the input section before the first bend is parallel to the second arm portion of the input section before the second bend. In some non-limiting embodiments, the first arm portion has a third bend located at the transition of the first arm portion between the middle section and the output section, the second arm portion has a fourth bend located at the transition of the second arm portion between the middle section and the output section, and the first arm portion of the output section after the third bend is parallel to the second arm portion of the output section after the fourth bend.

[0044] In some non-limiting embodiments, the span of the first arm portion in the middle section has a different width than the width of the span of the second arm portion in the middle section. In some non-limiting embodiments, the first span of the first arm portion in the middle section has a different width than the width of the second span of the first arm portion in the middle section. In some non-limiting embodiments, the first span of the second arm portion in the middle section has a different width than the width of the second span of the second arm portion in the middle section. In some non-limiting embodiments, the input segment is a first input segment of the first stage, wherein the middle segment is a first middle segment of the first stage, and wherein the output segment is a first output segment of the first stage. In some non-limiting embodiments, the optical waveguide interferometer may also include a second stage, which may include a second input segment, a second middle segment, a second output segment, and the first output segment of the first stage is coupled to the second input segment of the second stage.

[0045] In this way, the optical waveguide interferometer can allow for a design with a compact size suitable for specific applications such as planar photonic integrated circuits. In addition, the optical waveguide interferometer can allow for minimal overbending (e.g., minimum number of turns, turns without sharp bends, etc.) to allow for proper routing of optical signals through the optical waveguide interferometer that reduces attenuation, undesirable interference, and minimizes signal loss. In addition, the shape of the arm portion can have a size and configuration that allows for a compact design for specific applications such as a finite impulse response (FIR) lattice filter.

[0046] See now Figure 1 , Figure 1is a diagram of a non-limiting embodiment of an optical waveguide interferometer 100. Figure 1 As shown in FIG. 1 , the optical waveguide interferometer 100 may include an input section 102, an intermediate section 104, and an output section 106. Figure 1 As further shown in , the optical waveguide interferometer 100 may include a short arm portion referred to as a first arm portion 108 spanning the input section 102, the middle section 104, and the output section 106, and a long arm portion referred to as a second arm portion 110 spanning the input section 102, the middle section 104, and the output section 106. The short arm portion may have a length shorter than the length of the long arm portion. In some non-limiting embodiments, the length of the first arm portion 108 is less than the length of the second arm portion 110. In some non-limiting embodiments, the optical waveguide interferometer 100 may have a length between about 175 μm-200 μm (e.g., the length measured from the input section 102 to the output section 106) and a width of about 50 μm-60 μm (e.g., the width measured from the highest point of the second arm portion 110 to a point on the first arm portion 108 that is orthogonal to the highest point). In some non-limiting embodiments, the second arm portion 110 has a curved shape. For example, a portion of the second arm portion 110 spanning the middle section 104 of the optical waveguide interferometer 100 may have a curved shape. In some non-limiting embodiments, the curved shape may be a shape having a curvature less than 90 degrees.

[0047] In some non-limiting embodiments, a portion of the second arm portion 110 (e.g., a portion of the second arm portion 110 that spans the middle section 104 of the optical waveguide interferometer 100) may have a curved shape that is planar with (e.g., in the same plane as) a portion of the first arm portion 108 (e.g., a portion of the first arm portion 108 that spans the middle section 104 of the optical waveguide interferometer 100). For example, a portion of the second arm portion 110 may extend in two dimensions in the same manner that a portion of the first arm portion 108 may extend.

[0048] In some non-limiting embodiments, a portion of the second arm portion 110 can have a shape (e.g., a curved shape) that is not in the same plane as a portion of the first arm portion 108. For example, a portion of the second arm portion 110 that spans the middle section 104 can be located in a plane that is orthogonal to a plane in which a portion of the first arm portion 108 that spans the middle section 104 is located. In some non-limiting embodiments, a portion of the second arm portion 110 and / or a portion of the first arm portion 108 can have a three-dimensional configuration.

[0049] In some non-limiting embodiments, the first arm portion 108 can have a first bend 112 between the input section 102 and the intermediate section 104. For example, the first arm portion 108 can have a first bend 112 located at a transition of the first arm portion 108 between the input section 102 and the intermediate section 104. In some non-limiting embodiments, the second arm portion 110 can have a second bend 114 between the input section 102 and the intermediate section 104.

[0050] In some non-limiting embodiments, the first arm portion 108 can have a third bend 116 between the intermediate section 104 and the output section 106. For example, the first arm portion 108 can have a third bend 116 located at the transition of the first arm portion 108 between the intermediate section 104 and the output section 106. In some non-limiting embodiments, the second arm portion 110 can have a fourth bend 118 between the intermediate section 104 and the output section 106. For example, the second arm portion can have a fourth bend 118 located at the transition of the second arm portion 110 between the intermediate section 104 and the output section 106.

[0051] like Figure 1 As further shown in FIG. 1 , the opening angle, represented as the first angle 120, is defined by (e.g., between) the first arm portion 108 adjacent to the input section 102 (e.g., a portion of the first arm portion 108 after the second bend 114, the second bend 114 being located at the transition of the first arm portion 108 between the input section 102 and the intermediate section 104) and the second arm portion 110 (e.g., a portion of the second arm portion 110 after the second bend 114 being located at the transition of the second arm portion 110 between the input section 102 and the intermediate section 104). For example, the first arm portion 108 after the first bend 112, the first bend 112 being located at the transition of the first arm portion 108 between the input section 102 and the intermediate section 104, and the second bend 114 being located at the transition of the second arm portion 110 between the input section 102 and the intermediate section 104, forms the first angle 120. In some non-limiting embodiments, the first angle 120 may be in the range of approximately 5-70 degrees.

[0052] In some non-limiting embodiments, the first angle 120 can be defined based on the angle between two lines, such as lines 124a and 124b. In some non-limiting embodiments, line 124a can be a line parallel to and along the first arm portion 108 (e.g., concentric with the first arm portion 108, along the inner edge of the first arm portion 108, etc.). In some non-limiting embodiments, line 124b can be a line tangent to an inflection point in the second arm portion 110. For example, line 124b can be a line tangent to a point where the shape of the second arm portion transitions from a positive curvature to a negative curvature or from a negative curvature to a positive curvature. In another example, line 124b can be a line tangent to a point where the shape of the second arm portion transitions from a positive curvature or a negative curvature to no curvature (e.g., zero curvature).

[0053] like Figure 1 As further shown in FIG. 1 , a closed angle, indicated as a second angle 122, is defined by the first arm portion 108 adjacent to the output section 106 (e.g., a portion of the first arm portion 108 before the fourth bend 118, the fourth bend 118 being located at the transition of the first arm portion 108 between the intermediate section 104 and the output section 106) and the second arm portion 110 (e.g., a portion of the second arm portion 110 before the fourth bend 118, the fourth bend 118 being located at the transition of the second arm portion 110 between the intermediate section 104 and the output section 106). For example, the first arm portion 108 after the third bend 116, the third bend 116 being located at the transition of the first arm portion 108 between the intermediate section 104 and the output section 106, and the fourth bend 118 being located at the transition of the second arm portion 110 between the intermediate section 104 and the output section 106, form the second angle 122. In some non-limiting embodiments, the second angle 122 may be in the range of approximately 5-70 degrees.

[0054] In some non-limiting embodiments, the first angle 122 can be defined based on the angle between two lines, such as lines 126a and 126b. In some non-limiting embodiments, line 126a can be a line parallel to and along the first arm portion 108 (e.g., concentric with the first arm portion 108, along the inner edge of the first arm portion 108, etc.). In some non-limiting embodiments, line 126b can be a line tangent to an inflection point in the second arm portion 110. For example, line 126b can be a line tangent to a point where the shape of the second arm portion transitions from a positive curvature to a negative curvature or from a negative curvature to a positive curvature. In another example, line 126b can be a line tangent to a point where the shape of the second arm portion transitions from a positive curvature or a negative curvature to no curvature (e.g., zero curvature).

[0055] In some non-limiting embodiments, the first angle 120 and the second angle 122 can be equal. In some non-limiting embodiments, the first angle 120 and / or the second angle 122 can be sized and configured to achieve a specific length imbalance between the first arm portion 108 and the second arm portion 110.

[0056] In some non-limiting embodiments, the first arm portion 108 extends in a straight line along the intermediate section 104. For example, the first arm portion 108 extends in a straight line from a first bend 112 located at the transition of the first arm portion 108 between the input section 102 and the intermediate section 104 to a third bend 116 located at the transition between the intermediate section 104 and the output section 106. In some non-limiting embodiments, a portion of the first arm portion 108 can be parallel to a portion of the second arm portion 110 (e.g., can extend in a direction parallel to a portion of the second arm portion 110). For example, the first arm portion 108 can be parallel to the second arm portion 110 at the input section 102. In another example, the first arm portion 108 can be parallel to the second arm portion 110 at the output section 106.

[0057] See now Figure 2 , Figure 2 2 is a diagram illustrating the curved shape of the second arm portion 110 of the optical waveguide interferometer 200. Figure 2 As shown in , the second arm portion 110 can be bent to produce a longer path length than the path of the first arm portion 108. In one example, a Bezier curve with an adiabatic transition from a straight line to a curved curvature can be used for the curved shape of the second arm portion 110. In some non-limiting embodiments, the bending radius 210 of the curved shape (e.g., a waveguide curve) can start from a straight line segment or a curved portion with a very large bending radius, which then reaches a critical value (e.g., about 100 μm) in the middle of the curved portion. In some non-limiting embodiments, the curved shape can be a shape with a curvature 220 of less than 90 degrees. In one example, the curved shape can be a shape with a curvature 220 of about 49 degrees (e.g., 49.8484375 degrees). In another example, the curved shape can be a shape with a curvature 220 of about 69 degrees (e.g., 69.57890625 degrees).

[0058] See now Figure 3 , Figure 3 is a diagram of a non-limiting embodiment of an optical waveguide interferometer 300 having multiple stages. Figure 3As shown in FIG. 1 , the optical waveguide interferometer 300 may include a first stage 328a, a second stage 328b, and a third stage 328c. In some non-limiting embodiments, one or more of the first stage 328a, the second stage 328b, and the third stage 328c may be the same or similar to the optical waveguide interferometer 100. For example, one or more of the first stage 328a, the second stage 328b, and the third stage 328c may include the same as described above. Figure 1 The optical waveguide interferometer 100 may be the same or similar components as described above. In some non-limiting embodiments, one or more of the first stage 328a, the second stage 328b, and the third stage 328c may be sized and configured in the same manner. For example, the first stage 328a, the second stage 328b, and the third stage 328c may have the same size and configuration.

[0059] like Figure 3 As further shown in FIG. 1 , the first stage 328a may include a first input section 302a, a first intermediate section 304a, and a first output section 306a; the second stage 328b may include a second input section 302b, a second intermediate section 304b, and a second output section 306b; and the third stage 328c may include a third input section 302c, a third intermediate section 304c, and a third output section 306c. Figure 3 As further shown in FIG. 1 , the first output segment 306a of the first stage 328a can be connected to (e.g., coupled to) the second input segment 302b of the second stage 328b, and the second output segment 306b of the second stage 328 can be connected to the third input segment 302c of the third stage 328c. Additional stages can be connected in the same or similar manner. Figure 3 As further shown in FIG. 1 , an optical coupler device 330 can be connected to the first input section 302a of the first stage 328a. In some non-limiting embodiments, the optical coupler device 330 can include a device capable of distributing an optical signal from one optical fiber (e.g., or waveguide) to two or more optical fibers (e.g., two or more waveguides) and / or combining optical signals from two or more optical fibers into a single optical fiber. In some non-limiting embodiments, the optical coupler device 330 can include a fiber optic coupler (e.g., a fiber coupler) and / or other similar devices. In some non-limiting embodiments, the optical coupler device 330 is designed and / or manufactured in the same manner as the first arm portion 108 and the second arm portion 110 of the optical waveguide interferometer 100.

[0060] like Figure 3 As further shown in FIG. 1 , a first angle 320a of the first stage 328a is defined by a first arm portion 308a and a second arm portion 310a adjacent to the first input section 302a, and a second angle 322a of the first stage 328a is defined by a first arm portion 308a and a second arm portion 310a adjacent to the output section 306a. Figure 3 As further shown in FIG. 1 , the second stage 328b and the third stage 328c may also include first angles 320b, 320c and second angles 322b, 322c, respectively. In some non-limiting embodiments, the first angles 320a, 320b, 320c and the second angles 322a, 322b, 322c may be respectively as described with respect to FIG. Figure 1 The first angle 120 and the second angle 122 shown and described are sized and configured in the same or similar manner. In some non-limiting embodiments, the first angles 320a, 320b, 320c and the second angles 322a, 322b, 322c can be equal. In some non-limiting embodiments, each set of angles for a given level can be equal, but one level may be different from another level. For example, the first angle 320a and the second angle 322a can be equal to each other, and the first angle 320b and the second angle 320b can be equal to each other, and the first angle 320a and / or the second angle 322a can be different from the first angle 320b and the second angle 320b.

[0061] like Figure 3 As further shown in FIG. 1 , a first axis 342 is shown along (e.g., concentric with) a first arm portion 308a of a first stage 328a, and a second axis 344 is shown along a first arm portion 308b of a second stage 328b. In some non-limiting embodiments, a first stage angle 346 can be defined by the first axis 342 and the second axis 344. In some non-limiting embodiments, the first stage angle 346 can provide a degree of alignment between the first stage 328a and the second stage 328b.

[0062] like Figure 3 As further shown in FIG. 1 , the orientation of the first stage 328a can be opposite (e.g., flipped) compared to the orientation of the second stage 328b. For example, the second arm portion 310a of the first stage 328a can be located on a first side of the first arm portion 308a, and / or the first arm portion 308b and the second arm portion 310b of the second stage 328b can be located on a second side of the first arm portion 308a and / or the first arm portion 308b, wherein the first side and the second side are generally opposite to each other with respect to the first arm portion 308a and / or the first arm portion 308b.

[0063] like Figure 3As further shown in FIG. 3 , the third axis 348 is shown as being along the first arm portion 308c of the third stage 328c. In some non-limiting embodiments, the second stage angle 350 can be defined by the second axis 344 and the third axis 348. In some non-limiting embodiments, the second stage angle 350 can provide a certain degree of alignment between the second stage 328b and the third stage 328c. In some non-limiting embodiments, the first stage angle 346 and the second stage angle 350 can be equal. In some non-limiting embodiments, the first stage angle 346 and the second stage angle 350 can be different. In some non-limiting embodiments, the first stage angle 346 and the second stage angle 350 can be selected to provide a predetermined form factor for the optical waveguide interferometer 300. In this way, the size and configuration of the optical waveguide interferometer 300 can be determined based on the first stage angle 346 and the second stage angle 350. Additionally or alternatively, the size and configuration of the optical waveguide interferometer 300 may be determined based on the orientation of the first stage 328a, the second stage 328b, and / or the third stage 328c (e.g., with respect to the orientation of one stage relative to another stage). Additionally or alternatively, the size and configuration of the optical waveguide interferometer 300 may be determined based on the first angle 320a, 320b, 320c and the second angle 322a, 322b, 322c.

[0064] See now Figure 4 , Figure 4 is a diagram of a non-limiting embodiment of an optical waveguide interferometer 400. Figure 4 As shown in FIG. 4 , the optical waveguide interferometer 400 may include a first stage 428a, a second stage 428b, and a third stage 428c. In some non-limiting embodiments, one or more of the first stage 428a, the second stage 428b, and the third stage 428c may be the same or similar to the optical waveguide interferometer 100 or the optical waveguide interferometer 300 (e.g., one or more stages of the optical waveguide interferometer 300). For example, one or more of the first stage 428a, the second stage 428b, and the third stage 428c may include the same as described above. Figure 1 The optical waveguide interferometer 100 or the Figure 3 The optical waveguide interferometer 300 may be the same or similar components as described above. In some non-limiting embodiments, one or more of the first stage 428a, the second stage 428b, and the third stage 428c may be sized and configured in the same manner. For example, the first stage 428a, the second stage 428b, and the third stage 428c may have the same size and configuration.

[0065] like Figure 4As further shown in FIG. 4 , the first stage 428a may include a first input section 402a, a first intermediate section 404a, and a first output section 406a; the second stage 428b may include a second input section 402b, a second intermediate section 404b, and a second output section 406b; and the third stage 428c may include a third input section 402c, a third intermediate section 404c, and a third output section 406c. Figure 4 As further shown in FIG. 4 , the first output segment 406a of the first stage 428a may be connected to (e.g., coupled to) the second input segment 402b of the second stage 428b, and the second output segment 406b of the second stage 428b may be connected to the third input segment 402c of the third stage 428c. Figure 4 As further shown in FIG. 4 , the first arm portion 408a of the first stage 428a may include a span 424a, the second arm portion 410a of the first stage 428 may include a span 426a, the first arm portion 408b of the second stage 428b may include a span 424b, the second arm portion 410b of the second stage 428b may include a span 426b, the first arm portion 408c of the third stage 428c may include a span 424c, and the second arm portion 410c of the third stage 428c may include a span 426c.

[0066] like Figure 4As further shown in FIG. 4 , the span 424a of the first arm portion 408a can have a first width (e.g., a first predetermined width), and the span 426a of the second arm portion 410a can have a second width. In some non-limiting embodiments, the first width of the span 424a of the first arm portion 408a can be different from the second width of the span 426a of the second arm portion 410a. In one example, the first width of the span 424a of the first arm portion 408a can be less than the second width of the span 426a of the second arm portion 410a. In another example, the first width of the span 424a of the first arm portion 408a can be greater than the second width of the span 426a of the second arm portion 410a. In some non-limiting embodiments, the span 424a of the first arm portion 408a can have a first width extending along one or more segments (e.g., only one segment, multiple segments, etc.) of the first input segment 402a, the first intermediate segment 404a, and / or the first output segment 406a of the first stage 428a. For example, the span 424a of the first arm portion 408a can be located in the first intermediate section 404a. In some non-limiting embodiments, the span 426a of the second arm portion 410a can have a second width extending along one or more of the first input section 402a, the first intermediate section 404a, and / or the first output section 406a of the first stage 428a. For example, the span 426a of the second arm portion 410a can be located in the first intermediate section 404a. Additionally or alternatively, the span 424b and / or the span 424c can be the same or similar to the span 424a (e.g., can have the same characteristics in terms of width, positioning, etc.). Additionally or alternatively, the span 426b and / or the span 426c can be the same or similar to the span 426a.

[0067] See now Figure 5 , Figure 5 5 is a diagram of a non-limiting embodiment of an optical waveguide interferometer 500. In some non-limiting embodiments, the optical waveguide interferometer 500 may be the same as or similar to the optical waveguide interferometer 100, the optical waveguide interferometer 300 (e.g., one or more stages of the optical waveguide interferometer 300), or the optical waveguide interferometer 400 (e.g., one or more stages of the optical waveguide interferometer 400). For example, the optical waveguide interferometer 500 may include the same as described above. Figure 1 The optical waveguide interferometer 100, as described in Figure 3 The optical waveguide interferometer 300, or as described in Figure 4 The optical waveguide interferometer 400 may have the same or similar components.

[0068] like Figure 5 As shown in FIG. 5 , the optical waveguide interferometer 500 may include an input section 502, an intermediate section 504, and an output section 506. Figure 5As further shown in FIG. 5 , the optical waveguide interferometer 500 may include a short arm portion referred to as a first arm portion 508 spanning the input segment 502, the middle segment 504, and the output segment 506, and a long arm portion referred to as a second arm portion 510 spanning the input segment 502, the middle segment 504, and the output segment 506. Figure 5 As further shown in FIG. 5 , the first arm portion 508 may include a first span 524a and a second span 524b. Figure 5 As further shown in FIG. 5 , the second arm portion 510 can include a first span 526a and a second span 526b.

[0069] In some non-limiting embodiments, the first span 524a of the first arm portion 508 can have a different width than the width of the second span 524b of the first arm portion 508. In one example, the first span 524a of the first arm portion 508 can have a greater width than the width of the second span 524b of the first arm portion 508. In another example, the first span 524a of the first arm portion 508 can have a lesser width than the width of the second span 524b of the first arm portion 508. In some non-limiting embodiments, the first span 524a of the first arm portion 508 can have a different length than the length of the second span 524b of the first arm portion 508. In one example, the first span 524a of the first arm portion 508 can have a greater length than the length of the second span 524b of the first arm portion 508. In another example, the first span 524a of the first arm portion 508 can have a lesser length than the length of the second span 524b of the first arm portion 508. In some non-limiting embodiments, the first span 524a of the first arm portion 508 may have a length equal to a length of the second span 524b of the first arm portion 508 .

[0070] In some non-limiting embodiments, the first span 524a and the second span 524b of the first arm portion 508 may be located at the same section of the first arm portion 508. For example, the first span 524a and the second span 524b of the first arm portion 508 may be located at the middle section 504 of the optical waveguide interferometer 500. In some non-limiting embodiments, the first span 524a and the second span 524b of the first arm portion 508 may be located at different sections of the first arm portion 508. For example, the first span 524a of the first arm portion 508 may be located at the input section 502 of the optical waveguide interferometer 500, and the second span 524b may be located at the middle section 504 of the optical waveguide interferometer 500.

[0071] In some non-limiting embodiments, the first span 526a of the second arm portion 510 can have a different width than the width of the second span 526b of the second arm portion 510. In one example, the first span 526a of the second arm portion 510 can have a width that is greater than the width of the second span 526b of the second arm portion 510. In another example, the first span 526a of the second arm portion 510 can have a width that is less than the width of the second span 526b of the second arm portion 510. In some non-limiting embodiments, the first span 526a of the second arm portion 510 can have a different length than the length of the second span 526b of the second arm portion 510. In one example, the first span 526a of the second arm portion 510 can have a length that is greater than the length of the second span 526b of the second arm portion 510. In another example, the first span 526a of the second arm portion 510 can have a length that is less than the length of the second span 526b of the second arm portion 510. In some non-limiting embodiments, the first span 526 a of the second arm portion 510 may have a length equal to a length of the second span 526 b of the second arm portion 510 .

[0072] In some non-limiting embodiments, the first span 526a and the second span 526b of the first arm portion 508 may be located at the same section of the first arm portion 508. For example, the first span 526a and the second span 526b of the second arm portion 510 may be located at the middle section 504 of the optical waveguide interferometer 500. In some non-limiting embodiments, the first span 526a and the second span 526b of the second arm portion 510 may be located at different sections of the first arm portion 508. For example, the first span 526a of the second arm portion 510 may be located at the input section 502 of the optical waveguide interferometer 500, and the second span 526b may be located at the middle section 504 of the optical waveguide interferometer 500.

[0073] In some non-limiting embodiments, the first span 524a and / or the second span 524b of the first arm portion 508 can have a different width than the width of the first span 526a and / or the second span 526b of the second arm portion 510. In one example, the first span 524a and / or the second span 524b of the first arm portion 508 can have a greater width than the width of the first span 526a and / or the second span 526b of the second arm portion 510. In another example, the first span 524a and / or the second span 524b of the first arm portion 508 can have a lesser width than the width of the first span 526a and / or the second span 526b of the second arm portion 510.

[0074] In some non-limiting embodiments, the first span 524a and / or the second span 524b of the first arm portion 508 can have a length that is different from the length of the first span 526a and / or the second span 526b of the second arm portion 510. In one example, the first span 524a and / or the second span 524b of the first arm portion 508 can have a length that is greater than the length of the first span 526a and / or the second span 526b of the second arm portion 510. In another example, the first span 524a and / or the second span 524b of the first arm portion 508 can have a length that is less than the length of the first span 526a and / or the second span 526b of the second arm portion 510. In some non-limiting embodiments, the first span 524a and / or the second span 524b of the first arm portion 508 can have a length that is equal to the length of the first span 526a and / or the second span 526b of the second arm portion 510.

[0075] In some non-limiting embodiments, the first span 524a and / or the second span 524b of the first arm portion 508 may be located at the same section of the optical waveguide interferometer 500 as the first span 526a and / or the second span 526b of the second arm portion 510. For example, the first span 524a and / or the second span 524b of the first arm portion 508 and the first span 526a and / or the second span 526b of the second arm portion 510 may be located at the middle section 504 of the optical waveguide interferometer 500. In some non-limiting embodiments, the first span 524a and / or the second span 524b of the first arm portion 508 may be located at a different section of the optical waveguide interferometer 500 than the first span 526a and / or the second span 526b of the second arm portion 510. For example, the first span 524a and / or the second span 524b of the first arm portion 508 may be located at the input section 502 of the optical waveguide interferometer 500 , while the first span 526a and / or the second span 526b of the second arm portion 510 may be located at the middle section 504 of the optical waveguide interferometer 500 .

[0076] See now Figure 6 , Figure 6 is a diagram of a non-limiting embodiment of an optical waveguide interferometer 600. Figure 6As shown in , the optical waveguide interferometer 600 may include a first stage 628a, a second stage 628b, a third stage 628c, and a fourth stage 628d. In some non-limiting embodiments, one or more of the first stage 628a, the second stage 628b, the third stage 628c, and the fourth stage 628d may be the same or similar to the optical waveguide interferometer 100, the optical waveguide interferometer 300 (e.g., one or more stages of the optical waveguide interferometer 300), the optical waveguide interferometer 400 (e.g., one or more stages of the optical waveguide interferometer 400), or the optical waveguide interferometer 500 (e.g., one or more stages of the optical waveguide interferometer 500). For example, one or more of the first stage 628a, the second stage 628b, the third stage 628c, and the fourth stage 628d may include the same as described with respect to Figure 1 The optical waveguide interferometer 100, as described in Figure 3 The optical waveguide interferometer 300, as described in Figure 4 The optical waveguide interferometer 400, or as described in Figure 5 The optical waveguide interferometer 500 may have the same or similar components.

[0077] like Figure 6 As further shown in FIG. 6 , the optical waveguide interferometer 600 may include a first stage 628a, a second stage 628b, a third stage 628c, and a fourth stage 628d connected together. For example, the first stage 628a is connected in series to the second stage 628b, the second stage 628b is connected in series to the third stage 628c, and the third stage 628c is connected in series to the fourth stage 628d. In some non-limiting embodiments, one or more of the first stage 628a, the second stage 628b, the third stage 628c, and the fourth stage 628d may be connected together in the same or similar manner as the first stage 328a, the second stage 328b, and the third stage 328c of the optical waveguide interferometer 300. In some non-limiting embodiments, one or more of the first stage 628a, the second stage 628b, the third stage 628c, and the fourth stage 628d may be sized and configured in the same manner. For example, the first stage 628a, the second stage 628b, the third stage 628c, and the fourth stage 628d may have the same size and configuration.

[0078] like Figure 6 As further shown in FIG. 6 , the first stage 628a may include a first input section 602a, a first intermediate section 604a, and a first output section 606a; the second stage 628b may include a second input section 602b, a second intermediate section 604b, and a second output section 606b; the third stage 628c may include a third input section 602c, a third intermediate section 604c, and a third output section 606c; and the fourth stage 628d may include a fourth input section 602d, a fourth intermediate section 604d, and a fourth output section 606d. Figure 6As further shown in FIG. 6 , the stages 628a-628d may include first arm portions 608a-608d and second arm portions 610a-610d, respectively. Figure 6 As further shown in FIG. 1 , the first output segment 606a of the first stage 628a can be connected to (e.g., coupled to) the second input segment 602b of the second stage 628b, the second output segment 606b of the second stage 628b can be connected to the third input segment 602c of the third stage 628c, and the third output segment 606c of the third stage 628c can be connected to the fourth input segment 602d of the fourth stage 628d. Additional stages can be connected in the same or similar manner.

[0079] like Figure 6 As further shown in FIG. 6 , the first output segment 606a of the first stage 628a can be configured to be parallel to the second input segment 602b of the second stage 628b. Figure 6 As further shown in FIG. 6 , a first axis 642 is shown along (e.g., concentric with) a first arm portion 608a of a first stage 628a, and a second axis 644 is shown along a first arm portion 608b of a second stage 628b. In some non-limiting embodiments, a first stage angle 646 can be defined by the first axis 642 and the second axis 644. In some non-limiting embodiments, the first stage angle 646 can provide a degree of alignment between the first stage 628a and the second stage 628b.

[0080] In some non-limiting embodiments, one or more stages of the optical waveguide interferometer 600 may be configured to be linearly aligned. Figure 6 As further shown in FIG. 6 , the first axis 642 is shown along (e.g., concentric with) the first arm portion 608b of the second stage 628b, the first arm portion 608c of the third stage 628c, and the first arm portion 608d of the fourth stage 628d. In this way, the second stage 628b, the third stage 628c, and the fourth stage 628d can be linearly aligned to provide a desired form factor.

[0081] like Figure 6 As further shown in FIG. 6 , the second output segment 606b of the second stage 628b can be configured to be non-parallel with the third input segment 602c of the third stage 628c, and the third output segment 606c of the third stage 628c can be configured to be non-parallel with the fourth input segment 602d of the fourth stage 628d. By configuring the output segments of a stage to be non-parallel with the input segments of other stages, the design of the optical waveguide interferometer 600 can reduce or eliminate net rotational bending based on increasing the number of stages and straightening the design of the optical waveguide interferometer 600. In addition, this can also illustrate a relatively wavelength-independent optical tap ratio for specific applications such as lattice filters.

Claims

1. An optical waveguide interferometer, comprising: Input segment; middle section; Output section; a first arm portion having a first length spanning the input segment, the intermediate segment, and the output segment; as well as a second arm portion having a second length spanning the input segment, the intermediate segment, and the output segment; wherein a first length of the first arm portion is less than a second length of the second arm portion; and The second arm portion has a curved shape.

2. The optical waveguide interferometer of claim 1 , wherein the first arm portion has a first bend located at a transition of the first arm portion between the input section and the intermediate section; and The second arm portion has a second bend located at the transition of the second arm portion between the input section and the middle section.

3. The optical waveguide interferometer of claim 2, wherein the first arm portion has a third bend located at a transition of the first arm portion between the intermediate section and the output section; and The second arm portion has a fourth bend located at a transition of the second arm portion between the middle section and the output section.

4. The optical waveguide interferometer of claim 3, wherein the first angle is defined by a first arm portion after a first bend and a second arm portion after a second bend, the first bend being located at a transition of the first arm portion between an input section and an intermediate section, the second bend being located at a transition of the second arm portion between the input section and the intermediate section; and wherein the second angle is defined by the first arm portion before a third bend and the second arm portion before a fourth bend, the third bend being located at a transition of the first arm portion between the middle section and the output section, the fourth bend being located at a transition of the second arm portion between the middle section and the output section; and The first angle and the second angle are equal.

5. The optical waveguide interferometer of claim 1 , wherein the first arm portion has a first bend located at a transition of the first arm portion between the input section and the intermediate section; and The first arm portion extends in a straight line to a third bend located at the transition between the middle section and the output section.

6. The optical waveguide interferometer of claim 1, wherein the first arm portion at the input section is parallel to the second arm portion at the input section.

7. The optical waveguide interferometer of claim 1, wherein the first arm portion at the output section is parallel to the second arm portion at the output section.

8. The optical waveguide interferometer of claim 1, wherein the first arm portion has a first bend located at a transition of the first arm portion between the input section and the intermediate section; wherein the second arm portion has a second bend located at a transition of the second arm portion between the input section and the intermediate section; and A first arm portion of the inlet section located before the first bend is parallel to a second arm portion of the inlet section located before the second bend.

9. The optical waveguide interferometer of claim 8, wherein the first arm portion has a third bend located at a transition of the first arm portion between the intermediate section and the output section; wherein the second arm portion has a fourth bend located at a transition of the second arm portion between the intermediate section and the output section; and The first arm portion of the outlet section located after the third bend is parallel to the second arm portion of the outlet section located after the fourth bend.

10. The optical waveguide interferometer of claim 1, wherein a span of the first arm portion in the middle section has a width different from a width of a span of the second arm portion in the middle section.

11. The optical waveguide interferometer of claim 1, wherein a first span of the first arm portion in the middle section has a width different from a width of a second span of the first arm portion in the middle section.

12. The optical waveguide interferometer of claim 1, wherein a first span of the second arm portion in the middle section has a width different from a width of a second span of the second arm portion in the middle section.

13. The optical waveguide interferometer of claim 1 , wherein the input segment is a first input segment of a first stage, wherein the intermediate segment is a first intermediate segment of a first stage, and wherein the output segment is a first output segment of a first stage, and the optical waveguide interferometer further comprises: The second level, wherein the second level comprises: The second input segment; the second middle section; a second output section; and Wherein a first output section of the first stage is coupled to a second input section of the second stage.

14. An optical waveguide interferometer, comprising: The first level includes: First input segment; a first intermediate section; and First output section; The first level also includes: a first short arm portion spanning the first input segment, the first intermediate segment, and the first output segment; and a first long arm portion spanning the first input segment, the first intermediate segment, and the first output segment; wherein a span of the first short arm portion in the first middle section is shorter than a span of the first long arm portion in the first middle section; and wherein the first long arm portion has a first curved shape; The second level includes: The second input segment; a second intermediate segment; and The second output section; The second level also includes: a second short arm portion spanning the second input segment, the second intermediate segment, and the second output segment; and a second long arm portion spanning the second input segment, the second intermediate segment, and the second output segment; wherein a span of the second short arm portion in the second middle section is shorter than a span of the second long arm portion in the second middle section; wherein the second long arm portion has a second curved shape; and Wherein a first output section of the first stage is coupled to a second input section of the second stage.

15. The optical waveguide interferometer of claim 14, wherein the first short arm portion has a first bend located at a transition of the first short arm portion between the first input section and the first intermediate section; wherein the first long arm portion has a second bend located at a transition of the first long arm portion between the first input section and the first intermediate section; wherein the first short arm portion has a third bend located at a transition of the first short arm portion between the first intermediate section and the first output section; wherein the first long arm portion has a fourth bend located at a transition of the first long arm portion between the first intermediate section and the first output section; wherein the first angle is defined by a first short arm portion after the first bend and a first long arm portion after the second bend; wherein the second angle is defined by a first short arm portion before the third bend and a first long arm portion before the fourth bend; wherein the first angle and the second angle are equal; wherein the second short arm portion has a fifth bend located at a transition of the second short arm portion between the second input section and the second intermediate section; wherein the second long arm portion has a sixth bend located at a transition of the second long arm portion between the second input section and the second intermediate section; wherein the second short arm portion has a seventh bend located at a transition of the second short arm portion between the second intermediate section and the second output section; wherein the second long arm portion has an eighth bend located at a transition of the second long arm portion between the second intermediate section and the second output section; wherein the third angle is defined by the second short arm portion after the fifth bend and the second long arm portion after the sixth bend; wherein the fourth angle is defined by the second short arm portion before the seventh bend and the second long arm portion before the eighth bend; and The third angle and the fourth angle are equal.

16. The optical waveguide interferometer of claim 14, wherein the first short arm portion has a first bend located at a transition of the first short arm portion between the first input section and the first intermediate section; wherein the first short arm portion extends in a straight line to a third bend located at a transition between the first intermediate section and the first output section; wherein the second short arm portion has a fifth bend located at a transition of the second short arm portion between the second input section and the second intermediate section; and The second short arm portion extends in a straight line to a seventh bend located at the transition between the second middle section and the second output section.

17. The optical waveguide interferometer of claim 14, wherein a span of the first short arm portion in the first middle section has a width different from a width of a span of the first long arm portion in the first middle section; and The span of the second short arm portion in the second middle section has a width different from the width of the span of the second long arm portion in the second middle section.

18. The optical waveguide interferometer of claim 14, wherein a first span of the first short arm portion in the first middle section has a width different from a width of a second span of the first short arm portion in the first middle section; and The third span of the second short arm portion in the second middle section has a width that is different from a width of the fourth span of the second short arm portion in the second middle section.

19. The optical waveguide interferometer of claim 14, wherein a first span of the first elongated arm portion in the first intermediate section has a width different from a width of a second span of the first elongated arm portion in the first intermediate section; and The third span of the second long arm portion in the second middle section has a width that is different from a width of the fourth span of the second long arm portion in the second middle section.

20. An optical waveguide interferometer, comprising: The first level includes: First input segment; a first intermediate section; and First output section; The first level also includes: a first short arm portion spanning the first input segment, the first intermediate segment, and the first output segment; and a first long arm portion spanning the first input segment, the first intermediate segment, and the first output segment; wherein a span of the first short arm portion in the first middle section is shorter than a span of the first long arm portion in the first middle section; and wherein the first long arm portion has a first curved shape; The second level includes: The second input segment; a second intermediate segment; and The second output section; The second level also includes: a second short arm portion spanning the second input segment, the second intermediate segment, and the second output segment; and a second long arm portion spanning the second input segment, the second intermediate segment, and the second output segment; wherein a span of the second short arm portion in the second middle section is shorter than a span of the second long arm portion in the second middle section; wherein the second long arm portion has a second curved shape; wherein the first output section of the first stage is coupled to the second input section of the second stage; and The first output section of the first stage is not parallel to the second input section of the second stage.

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