Ultrafast Modulated Vertical Cavity Surface Emitting Laser (VCSEL)

Abstract

To provide a system and a method for an ultrafast modulated vertical cavity surface emitting laser (VCSEL).SOLUTION: An exemplary optical device includes a light source and an electroabsorption modulated laser (EML) based structure over the light source, the electroabsorption modulated laser (EML) based structure includes a grating structure, the grating structure includes a plurality of grating lines, and the grating structure further includes a Pockels material disposed within the grating structure.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] Claim of priority

[0001] This application claims priority and benefit to U.S. Provisional Patent Application No. 63 / 532,778, filed on 15 August 2023, and U.S. Provisional Patent Application No. 63 / 575,281, filed on 5 April 2024. Each of the above applications is incorporated herein by reference in its entirety.

[0002]

[0002] Aspects of the present disclosure relate to optical communication-based solutions. More specifically, certain implementations of the present disclosure relate to methods and systems for the implementation and use of ultrafast modulated vertical-cavity surface-emitting lasers (VCSELs). [Background technology]

[0003]

[0003] The limitations and drawbacks of conventional diffraction gratings will become apparent to those skilled in the art by comparing such systems with some aspects of the present disclosure described in other parts of this application with reference to the drawings. [Overview of the project]

[0004]

[0004] A system and method for an ultrafast modulated vertical resonator surface-emitting laser (VCSEL) is provided, substantially shown in and / or described in relation to the figure, and more fully described in the claims.

[0005]

[0005] Further details of the above-mentioned and other advantages, aspects and novel features of the present disclosure and its exemplary embodiments will be better understood from the following description and drawings. [Brief explanation of the drawing]

[0006] [Figure 1A]

[0006] This figure shows an exemplary ultrafast modulated vertical cavity surface-emitting laser (VCSEL) according to the present disclosure, in which Pockels material is incorporated into an alternating mating grid for improved performance. [Figure 1B] This figure shows an exemplary ultrafast modulated vertical cavity surface-emitting laser (VCSEL) with Pockels material incorporated into an alternating mating grid for improved performance, as disclosed herein. [Figure 2]

[0007] This figure shows an example of a vertical-cavity surface-emitting laser (VCSEL). [Figure 3]

[0008] This figure shows an example of a photonic crystal surface-emitting laser (PCSEL). [Figure 4]

[0009] This figure shows an example of a higher-order distributed feedback polymer (DFB). [Figure 5A]

[0010] This figure shows an exemplary vertical-cavity surface-emitting laser (VCSEL) based field absorption modulation laser (EML) as described in this disclosure. [Figure 5B]

[0011] This figure shows an exemplary 3-contact vertical-cavity surface-emitting laser (VCSEL) based field absorption modulation laser (EML) as described in this disclosure. [Figure 5C]

[0012] This figure shows an exemplary 4-contact vertical-cavity surface-emitting laser (VCSEL) based field absorption modulation laser (EML) as described in this disclosure. [Figure 6]

[0013] This figure shows an exemplary high-contrast grid (HCG) structure according to the present disclosure. [Figure 7]

[0014] This figure shows the use of an exemplary high-contrast grating (HCG) structure as a reflectance modulator according to the present disclosure. [Figure 8]

[0015] This figure shows the use of an exemplary high-contrast grating (HCG) structure in wavefront modulation according to the present disclosure. [Figure 9]

[0016] This figure shows the use of an exemplary vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) incorporating a high-contrast grating (HCG) having a Pockels material as an intensity modulator, as disclosed herein. [Figure 10]

[0017] A diagram showing different processes for fabricating an electro-absorption modulator laser (EML) based on a vertical-cavity surface-emitting laser (VCSEL) incorporating a high-contrast grating (HCG) with a Pockels material according to the present disclosure. [Figure 11]

[0018] A diagram showing the phasing in an exemplary electro-absorption modulator laser (EML) based on a vertical-cavity surface-emitting laser (VCSEL) incorporating a high-contrast grating (HCG) with a Pockels material according to the present disclosure. [Figure 12]

[0019] A diagram showing the use of an exemplary electro-absorption modulator laser (EML) based on a vertical-cavity surface-emitting laser (VCSEL) incorporating a high-contrast grating (HCG) with a Pockels material according to the present disclosure in wavefront modulation. [Figure 13]

[0020] A diagram showing the use of an exemplary electro-absorption modulator laser (EML) based on a vertical-cavity surface-emitting laser (VCSEL) incorporating a high-contrast grating (HCG) with a Pockels material on a contact in wavefront modulation according to the present disclosure. [Figure 14]

[0021] A diagram showing the processing of incident external light in an exemplary electro-absorption modulator laser (EML) based on a vertical-cavity surface-emitting laser (VCSEL) having a high-contrast grating (HCG) structure incorporating a Pockels material according to the present disclosure. [Figure 15]

[0022] A diagram showing the use of an exemplary electro-absorption modulator laser (EML) based on a vertical-cavity surface-emitting laser (VCSEL) incorporating a high-contrast grating (HCG) with a Pockels material according to the present disclosure in polarization modulation. [Figure 16]

[0023] A diagram showing an exemplary deformation of a high-contrast grating (HCG) structure with a Pockels material according to the present disclosure. [Figure 17]

[0024] A diagram showing a first exemplary implementation of an interlocking electro-absorption modulator laser (EML)-based structure according to the present disclosure. [Figure 18]

[0025] This figure shows a second exemplary implementation of an alternating mating field absorption modulation laser (EML)-based structure according to the present disclosure. [Figure 19]

[0026] This figure shows a third exemplary implementation of the alternating mating field absorption modulation laser (EML)-based structure according to the present disclosure. [Figure 20]

[0027] This figure shows fourth and fifth exemplary implementations of the alternating mating field absorption modulated laser (EML)-based structure according to the present disclosure. [Figure 21]

[0028] This figure shows a sixth exemplary implementation of an alternating mating field absorption modulated laser (EML)-based structure according to the present disclosure. [Figure 22]

[0029] This figure shows an exemplary vertical-cavity surface-emitting laser (VCSEL) based field absorption modulation laser (EML) incorporating a high-contrast grating (HCG) having a Pockels material and a dielectric for the gate, as disclosed herein. [Figure 23]

[0030] This figure shows an example of a vertical-cavity surface-emitting laser (VCSEL) based optical device, one of which incorporates an electric field absorption modulated laser (EML) based design. [Modes for carrying out the invention]

[0007]

[0031] Figures 1A and 1B show an exemplary ultrafast modulated vertical cavity surface-emitting laser (VCSEL) according to the present disclosure, incorporating Pockels material within an alternating-fit grating to improve performance. Referring to Figures 1A and 1B, a vertical cavity surface-emitting laser (VCSEL) 100 (or a part thereof) having an alternating-fit grating is shown to achieve ultrafast modulation.

[0008]

[0032] In this regard, the VCSEL100 may include a semiconductor laser diode-based structure configured to emit a laser beam emission perpendicular to the top surface. For example, the VCSEL may include a distributed Bragg reflector (DBR)-based structure configured to function as a mirror parallel to the top surface, having an active region containing one or more quantum wells for laser light generation. One DBR structure may be placed on a substrate layer and a heat sink layer. This planar DBR mirror may include layers having alternating high refractive index (RI) and low refractive index materials.

[0009]

[0033] The thickness of each layer can be set to yield high reflectivity. For example, a thickness of one-quarter the laser wavelength in the material can yield light reflectivity exceeding 99%. The use of high reflectivity can be used to balance the short-axis length of the gain region. In one embodiment, p-type and n-type regions can be embedded between DBR mirrors, thereby forming a diode junction. This may require more complex semiconductor processing to ensure electrical contact with the active layer / region, but it can eliminate power loss in the DBR structure. Figure 1A shows an exemplary structure of VCSEL100.

[0010]

[0034] According to this disclosure, the performance of VCSELs can be improved, particularly with respect to the modulation capabilities and / or characteristics of VCSELs. Specifically, this can be done by incorporating adjustments and / or additions to the structure of the VCSEL, thereby resulting in improved performance without adding excessive cost and / or complexity.

[0011]

[0035] In this regard, during VCSEL operation, the drive current can be modulated, and furthermore, the output laser can be modulated. However, VCSEL modulation can be limited in some cases by various factors, including the escape time of photons from the cavity portion of the VCSEL. This loss of gain can be helpful, but even in this case, it still takes some time for the photons to escape. This limits the speed of modulation in VCSELs. The solution provided by this disclosure makes it possible to modulate faster than the photon escape time. This can be done, for example, by redirecting the beam in a way that allows it to overcome the photon escape time.

[0012]

[0036] For example, in various embodiments of this disclosure, an alternating-fit grating can be used in a VCSEL as shown in Figure 1A. In this regard, the alternating-fit grating may include a metal grating filled with a Pockels material, i.e., a material having a high Pockels coefficient (e.g., organic, Perkinamine® for KTO). The Pockels material can be selected based on predetermined selection criteria, such as ensuring that the high-contrast grating can bias the laser beam as described herein. The use of an alternating-fit grating can enable the generation of a “sub-lambda” (or “relatively small with respect to the distance to the fiber”) array of the beam that can be emitted from the top of the modulator by canceling interference on the far field according to the Huygens-Fresnel principle. This results in high (constructive) power or low (canceling) power coupled into the fiber / far field, for example, by changing the applied bias between two alternating-fit gratings. As a second part, this effect can be enhanced by a resonant effect, which can be incorporated into the cavity.

[0013]

[0037] In one exemplary embodiment, a high-contrast grating (HCG) based approach can be used. In this context, the HCG can be used to replace the upper distributed Bragg reflector (DBR) layer of a vertical-cavity surface-emitting laser (VCSEL). In this context, any suitable high-contrast grating (HCG) based design can be used to enable the desired improvement in modulation speed. Specifically, important considerations when selecting and configuring a high-contrast grating (HCG) structure to be used in a VCSEL to enhance the modulation performance of the VCSEL may include the ability to bias and apply gate tension to the laser beam. For example, as shown in the embodiment illustrated in Figure 1A, the high-contrast grating (HCG) may include etched structures, such as those having an in-plane periodic or quasi-periodic structure with alternating low and high refractive indices (RI) to achieve "out-of-plane" high reflectivity. Also, contacts can be placed on top of the HCG structure (as shown in Figure 1A). These contacts can effectively function as mirrors. The contacts may include metal or any suitable material. In some cases, the HCG structure can incorporate some kind of DBR material above the active layer / region.

[0014]

[0038] In one exemplary embodiment, a metal array can be used to connect contacts on the surface of each HCG, for example. This is shown in Figure 1B, which shows a top view of a metal array placed on a VCSEL. The metal array can be used as an alternating mating gate having an etched, filled high-contrast grating (HCG) (e.g., DOI: 10.1038 / srep40348) of the VCSEL, which has holes filled with Pockels material. In this regard, the Pockels material does not need to meet specific filling criteria (e.g., it may be used to completely fill the holes, but this is not required). Rather, other factors may be important, such as the overlap between two different paths and the selection of the material used. In this regard, the Pockels coefficient of the material needs to allow biasing of the laser beam, for example, to ensure that canceling and constructive interference occurs as described herein. The metal wires of the metal array (i.e., contacts on the HCG) can be connected to each other and to V2 and can be insulated by a thin insulating layer. Similarly, Pockels material (pathways) filling the holes in the HCG structure can be connected to each other and to V1. Then, by biasing V2, half of the path can be defased relative to the second half, thereby causing a canceling interference.

[0015]

[0039] Notwithstanding the foregoing, the disclosure is not limited to such designs, and solutions based on the disclosure can be generalized to any suitable shape of the lattice, any material suitable for use in the lattice, and the use (or non-use) of resonance effects to enhance the Pockels effect.

[0016]

[0040] Furthermore, while various aspects and features of this disclosure based on VCSELs are illustrated and described based on implementation configurations, this disclosure is not limited to VCSELs, and similar designs described herein can be used in other types of light-emitting devices, such as photonic crystal surface-emitting lasers (PCSELs) and higher-order distributed feedback polymers (DFBs). Exemplary VCSELs, PCSELs, and higher-order DFBs configurable to incorporate structural and / or functional modifications based on this disclosure are shown and described with reference to Figures 2 to 4.

[0017]

[0041] Figure 2 shows an example of a vertical-cavity surface-emitting laser (VCSEL). Referring to Figure 2, a vertical-cavity surface-emitting laser (VCSEL) 200 (or a part thereof) is shown.

[0018]

[0042] VCSELs are commonly used as light sources (e.g., lasers) in implementations such as transceivers (e.g., optical transceivers used in data centers). Traditionally, VCSELs have been used with DC (I dc ) and interaction (I ac It is driven using one or both of the following.

[0019]

[0043] As shown in Figure 2, the VCSEL200 includes a multiple quantum well (MQW) layer that acts as a gain medium sandwiched between two mirrors (e.g., a distributed Bragg reflector (DBR) layer). The VCSEL200 also includes contacts on the top surface of the upper mirror layer and / or on the bottom surface of the VCSEL200, etc. The contacts may include, for example, a metallic material.

[0020]

[0044] Figure 3 shows an example of a photonic crystal surface-emitting laser (PCSEL). Referring to Figure 3, a photonic crystal surface-emitting laser (PCSEL) 300 (or a part thereof) is shown.

[0021]

[0045] PCSELs are commonly used as light sources (e.g., lasers), and conventionally, DC (I dc ) and interaction (I acIt is driven using one or both of the following.

[0046] As shown in Figure 3, the PCSEL300 includes a multiple quantum well (MQW) layer that functions as a gain medium sandwiched between a mirror (e.g., a distributed Bragg reflector (DBR)) layer on the bottom surface and a photonic crystal layer above the MQW layer. The PCSEL300 also includes contacts on the top surface of the upper mirror layer and / or on the bottom surface of the PCSEL300, etc. The contacts may include, for example, a metallic material.

[0022]

[0047] Figure 4 shows an example of a higher-order distributed feedback polymer (DFB). Referring to Figure 4, a higher-order distributed feedback polymer (DFB) 400 (or a part thereof) is shown.

[0048] Higher-order DFBs are commonly used as light sources (e.g., lasers), and conventionally, DC (I dc ) and interaction (I ac It is driven using one or both of the following.

[0023]

[0049] As shown in Figure 4, the higher-order DFB400 includes a multiple quantum well (MQW) layer that functions as a gain medium sandwiched between a mirror (e.g., distributed Bragg reflector (DBR)) layer on the bottom and a higher-order lattice layer above the MQW layer. The higher-order DFB400 also includes contacts on the top surface of the upper mirror layer and / or on the bottom surface of the higher-order DFB400, etc. The contacts may include, for example, a metallic material.

[0024]

[0050] Since the solutions based on this disclosure are also applicable to bottom-emitting devices, each of the three different types of optical devices shown in Figures 2 to 4 (VCSEL, PCSEL, and higher-order DFB) is shown using bottom-emitting devices.

[0025]

[0051] Figure 5A shows an example of a vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) as described in this disclosure. Referring to Figure 5A, a vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) 500 (or a part thereof) is shown.

[0026]

[0052] The VCSEL-EML500 includes a multiple quantum well (MQW) layer that acts as a gain medium sandwiched between two mirrors (e.g., a distributed Bragg reflector (DBR) layer), and has an electric absorption modulated laser (EML) base structure on the upper surface of the upper mirror layer. The VCSEL-EML500 may also include contacts on the upper surface of the EML base structure, on the upper surface of the upper mirror layer, and / or on the bottom surface of the VCSEL-EML500. The contacts may include, for example, a metallic material.

[0027]

[0053] VCSELs are commonly used as optical (e.g., laser) sources, particularly in implementations such as transceivers (e.g., optical transceivers used in data centers). Traditionally, direct-driven or DAC / DC-based VCSELs have been used. However, such direct-modulated VCSELs are approaching a bandwidth (BW) bottleneck between the electrical bandwidth and the optical bandwidth.

[0028]

[0054] Therefore, VCSEL-EML devices are used, in which an EML-based structure is added for use when processing at least a portion of the modulation performed in a VCSEL. In this regard, during the exemplary operation of a VCSEL-EML, a modulation voltage can be applied across the EML-based structure, and then current is supplied to drive the entire device. For example, the device can be driven using a time-varying voltage, which enables digitization-based driving (e.g., based on voltage on or off), such as a digital signal modulating the output optical signal. Alternatively, the device can be driven by a direct current (DC) so that it is always on. For example, as shown in Figure 5A, the VCSEL-EML500 uses V to drive the EML-based structure. ac It is used, on the other hand, to drive the device (as a whole). dc This is used.

[0029]

[0055] According to this disclosure, the performance of a VCSEL-EML (e.g., VCSEL-EML500) can be improved and / or optimized by specifically modifying the EML-based structure used herein. For example, a VCSEL-EML can be modified to implement a new modulation scheme, such as by incorporating a vertical EML that uses and / or utilizes the Pockels effect. In this regard, in such an implementation, the VCSEL can be used as a continuous-wave (CW) light source in which the proposed EML-based structure is monolithically mounted on top of the upper mirror (e.g., DBR) layer of the VCSEL. Furthermore, the EML can be modified to improve the performance of the EML and the overall device by specifically incorporating a Pockels material to utilize the Pockels effect.

[0030]

[0056] In this context, the Pockels effect is a directional, linear variation in the refractive index (RI) of an optical medium that occurs in response to the application of an electric field. The refractive index of an optical medium is a dimensionless number that gives an indicator of its ability to bend light. In other words, the refractive index is an indicator of the speed of light in a material. Therefore, in various implementations, Pockels materials are added to EML-based structures so that it is possible to modulate light based on the refractive index (RI) of the material (for example, by controlling the application of voltage across the Pockels material), and furthermore, so that when applied to an EML-based structure, it affects the behavior of the light beam.

[0031]

[0057] Such methods can be made material-independent, for example, by using an adaptation of the bias scheme on top of an EML-based structure. In this regard, the Pockels material used in EML can be adaptively selected and / or applied, as described herein, to ensure that specific performance criteria (determined, for example, in terms of desired or required RI) are met. Also, in many cases, the added Pockels material can be used in conjunction with a bias scheme (applicable to EML-based structures), and the bias scheme is adapted for the desired modulation function.

[0032]

[0058] For example, as shown in FIG. 5A, the VCSEL-EML 500 is implemented as an integrated three-contact VCSEL having a laser DC drive separated from the modulation drive. This enables the use of the EML electronic method by direct driving of the modulation section. By incorporating a Pockels material into the EML-based structure, performance improvement based on the adaptive use of the Pockels effect becomes possible. Specifically, the Pockels material can be used to enable the formation and / or use of sub-wavelength patterns for enhancing the Pockels effect.

[0033]

[0059] In various exemplary implementations, the EML can incorporate gratings configured to support the modulation function, and these gratings incorporate a Pockels material for utilizing the Pockels effect. For example, in one implementation, the incorporation of the Pockels material can be performed in combination with a high-contrast grating (HCG). In this regard, the use of the high-contrast grating (HCG) may be desirable because it can provide various advantages such as limited optical loss (e.g., << 3 dB), the ability to use a high Pockels material, and the ability to use the easily available simulation capabilities of the HCG. In some cases, an etching structure (e.g., width 50 nm to 100 nm, depth 200 nm to 400 nm) in a high refractive index material may be used.

[0034]

[0060] Depending on the configuration, the proposed EML-based structure may be used to provide various modulation functions. For example, the EML can be used to modulate the output power (intensity modulation or amplitude modulation) so as to modulate the beam deflection, for example, the output coupling into the fiber (wavefront modulation), and / or to modulate the beam polarization (polarization modulation).

[0035]

[0061] In some cases, the proposed EML-based structure can be configured to meet specific performance criteria. For example, the EML is the target V ΠIt may have a value of <<5V. To meet such performance standards, it may be necessary to design and / or configure EML-based structures accordingly. For example, such a target V Π To reliably satisfy this condition, for example, light field enhancement in Pockels materials may be necessary.

[0036]

[0062] In some cases, the EML-based structure proposed in this proposal can also be used for other applications, such as beam steering (e.g., as an ultrafast spatial optical modulator), or for providing 100Gbps components (e.g., passive optical network (PON) elements (on fiber tips, vertical modulators / couplers, etc.), MUX / DEMUX functions, etc.).

[0037]

[0063] In certain implementations, the proposed EML-based structure can be used with a photonic crystal surface-emitting laser (PCSEL) light source (instead of a VCSEL). The use of a PCSEL as a light source can be advantageous in certain cases, for example, optimizing the potential benefits of HCG design. In this regard, PCSELs may be optimal light sources because they are inherently single-mode devices, enabling the utilization of the full potential of the HCG's high-Q resonance and / or allowing for uniform illumination of the HCG (thus avoiding the undesirable finite-size effect of the HCG).

[0038]

[0064] Figure 5B shows an exemplary 3-contact vertical-cavity surface-emitting laser (VCSEL) based field absorption modulation laser (EML) according to the present disclosure. Referring to Figure 5B, a vertical-cavity surface-emitting laser (VCSEL) based field absorption modulation laser (EML) 520 (or a portion thereof) is shown.

[0039]

[0065] In this regard, the VCSEL-EML520 is substantially similar to and can operate substantially similarly to the VCSEL-EML500 in Figure 5A. Specifically, the VCSEL-EML520 includes an electric absorption modulated laser (EML)-based structure on top of a general-purpose vertical emission laser structure. The general-purpose vertical emission laser structure may include any suitable structure that can be configured to enable the laser to emit light in a vertical direction. For example, the general-purpose vertical emission laser structure may have a structure similar to the corresponding structure in the VCSEL-EML500 in Figure 5A, and therefore may include a multiple quantum well (MQW) layer that acts as a gain medium sandwiched between two mirrors (e.g., a distributed Bragg reflector (DBR) layer).

[0040]

[0066] Furthermore, the VCSEL-EML520 may include contacts on the top surface of the EML-based structure, on the top surface of the general-purpose vertical emission laser structure, and / or on the bottom surface of the general-purpose vertical emission laser structure, etc. The contacts may include, for example, a metallic material.

[0041]

[0067] The VCSEL-EML520 corresponds to an alternative design using three contacts. For example, in the embodiment shown in Figure 3B, the three contacts may correspond to a contact on the top surface of the EML-based structure, a contact on the top surface of the general-purpose vertical emission laser structure, and a contact on the bottom surface of the general-purpose vertical emission laser structure, respectively. These three contacts are I dc and / or V ac It is driven using

[0042]

[0068] Figure 5C shows an example of a 4-contact vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) as described herein. Referring to Figure 5B, a vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) 540 (or a portion thereof) is shown.

[0043]

[0069] In this regard, the VCSEL-EML540 can be substantially similar to the VCSEL-EML500 in Figure 5A and can operate substantially similarly. Specifically, the VCSEL-EML540 includes an electric absorption modulated laser (EML) based structure on a general-purpose vertical emission laser structure with an electrically insulating layer in between. The general-purpose vertical emission laser structure can include any suitable structure that can be configured to emit the laser vertically. For example, the general-purpose vertical emission laser structure may have a structure similar to the corresponding structure of the VCSEL-EML500 in Figure 5A, and thus may include a multiple quantum well (MQW) layer that acts as a gain medium sandwiched between two mirrors (e.g., a distributed Bragg reflector (DBR) layer).

[0044]

[0070] Furthermore, the VCSEL-EML540 may include contacts on the top surface of the EML-based structure, on the top surface of the general-purpose vertical emission laser structure, and / or on the bottom surface of the general-purpose vertical emission laser structure, etc. The contacts may include, for example, a metallic material.

[0045]

[0071] The VCSEL-EML540 corresponds to an alternative design using four contacts. For example, in the implementation shown in Figure 5C, the four contacts may correspond to contacts on the top surface of the EML-based structure, contacts on the top surface of the general-purpose vertical emission laser structure, and contacts on the bottom surface of the general-purpose vertical emission laser structure, respectively, and as shown in Figure 5, the contacts on the EML-based structure are configured into two separate groups of contacts. These four contacts are I dc and / or V ac It is driven using

[0046]

[0072] Figure 6 shows an exemplary high-contrast grating (HCG) structure according to this disclosure. Referring to Figure 6, a vertical-cavity surface-emitting laser (VCSEL) 600 incorporating a high-contrast grating (HCG) 610 is shown.

[0047]

[0073] The VCSEL600 includes two mirrors with an active layer (e.g., MQW) sandwiched between them, with the upper mirror incorporating HCG610. The lower and upper mirrors, along with the lattice structure, combine with the active layer to form a laser resonator.

[0048]

[0074] As described above, in some cases, a high-contrast grating (e.g., HCG610) may be used in a vertical-cavity surface-emitting laser (VCSEL) based field absorption modulation laser (EML) implemented under this disclosure, and HCG is used in particular to facilitate and / or support the modulation function performed by the EML-based structure in the EML-based structure of this proposal. In this regard, the grating incorporates grating features with gaps between them, and the height (dimension h) of the grating features, the width (dimension a) of the grating features, and the thickness (dimension h) of the contacts on the grating features. M ), the period of the grid features, i.e., the distance between identical points in consecutive grid features (dimension d), and the total depth of the gap (dimensions h and h when a contact is placed on the grid features shown in Figure 6). M It can be characterized by parameters such as combinations of [parameters].

[0049]

[0075] High-contrast gratings such as HCG610 can incorporate grating features with subwavelength dimensions and may have strong refractive index contrast (e.g., grating's air refractive index > 1.7). High contrast can be achieved by gaps that can be filled (e.g., by air with a very low RI), resulting in high contrast between the gaps and the grating structure features. In this context, the grating features are tall (and therefore the gaps are deep). In other words, the gaps can typically be deeper than their width to observe specular reflection effects.

[0050]

[0076] High-contrast gratings such as HCG610 can exhibit two modes: reflection (mode 0) and transmission (mode 2). As shown in Figure 6 (and Graph 620), in mode 0, the incident wave (applied from within the device, i.e., after propagating through the underlying substrate and then applied to the HCG from below) is reflected, while in mode 2, it passes through (as an output wave). In this context, the reflection mode / transmission mode can couple with each other and with plane waves. The transmission mode (mode 2) can be determined by canceling interference between grating features. For example, in a coupling formed by 50 / 50 (e.g., the geometry of the HCG), the canceling interference can be determined by Δβ / λ=Π.

[0051]

[0077] In various cases, high-contrast gratings can have two fundamental characteristics: 1) they can excite only a few modes, which can then be extracted externally as "plane waves," and 2) the modes can be squeezed in space, resulting in higher transverse momentum. Feature 1 involves blocking high spatial frequency components. Therefore, a two- or three-mode description of the HCG is sufficient to predict general behavior, with the other modes typically being evanescent. In this regard, such other modes can exist below the light cone and may enter quadratic when estimating the reflection / transmission properties at the HCG interface with air. Feature 2 involves reduced propagation constants and the possibility of canceling interference between modes (e.g., for structures in the <~ wavelength range).

[0052]

[0078] High-contrast gratings can exhibit different performance characteristics across different wavelength ranges. For example, in sub-wavelength dimensions, only one mode may exist in the structure, and Fabry-Perot (FP) nodes / antinodes may be observed as the HCG thickness increases. In super-wavelength dimensions, many modes may exist, and there is a periodic recovery of the input signal in a manner / pattern similar to the Talbot effect. Between these two ranges, only a few modes may exist. Also, at certain locations, two modes may resonate simultaneously within the HCG. For example, with a 2nπ phase difference, energy can be trapped inside the HCG, allowing for a large electric field enhancement (e.g., 1e3), which appears as anticrossing. With a (2n+1)π phase difference, some of this energy may be reflected from the HCG.

[0053]

[0079] In addition to their use in inducing optical resonance in devices such as VCSELs, high-contrast gratings can also be used in other applications such as beam manipulation (e.g., lenses, polarizers, diffractometers), wave guiding (e.g., MMIs, spot size converters, etc.), high broadband reflection, broadband anti-reflective coatings, nonlinear optics, biosensing, and chemical sensing.

[0054]

[0080] In the implementations based on this disclosure, Pockels material can be incorporated into the HCG structure, for example, by using Pockels material to fill at least a portion of the gaps between lattice features and / or to form lattice features (e.g., with contacts on top of them). In this regard, the use of Pockels material can improve the function of the HCG structure, particularly its modulation function. This will be further detailed below.

[0055]

[0081] Figure 7 illustrates the use of an exemplary high-contrast grating (HCG) structure as a reflectance modulator according to this disclosure. Referring to Figure 7, a vertical-cavity surface-emitting laser (VCSEL) 700 incorporating a high-contrast grating (HCG) is shown.

[0056]

[0082] The VCSEL700 may correspond to a vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) implemented under this disclosure, and HCG is used in the proposed EML-based structure to facilitate and / or support the modulation function performed by the EML. Figure 7 shows an example of HCG application, namely the use of HCG in an EML-based structure acting as a reflectance modulator.

[0057]

[0083] Such reflectance modulators can exhibit high electric field enhancement. For example, a silicon grid can produce a 2V "V Π A 30-fold electric field enhancement is possible. In addition, various aspects or features can be modified in some cases to further enhance performance. For example, in some cases, dimerized HCG (instead of ordinary HCG) can be used for better control. Also, different materials may be used for the lattice structure, such as using BaTiO3 or organic materials instead of silicon, which may provide greater tunability.

[0058]

[0084] In the exemplary operation of such reflectance modulators, for a beam propagating through an HCG (grille), there is a significant enhancement of the optical field if the beam has the appropriate wavelength (and / or the grille is properly designed). The electric field of the incident beam between the grilles is greater than the electric field of the incident beam before passing through the grille. Similarly, for a beam with the appropriate wavelength, the structure becomes reflective. The resonant frequency (where the beam is reflected without being passed through) can be controlled by adjusting the voltage applied to the grille. This is illustrated in the exemplary usage scenario 710 of the VCSEL700 and represented in Graph 720, which shows the transmittance as a function of wavelength.

[0059]

[0085] In the implementation based on this disclosure, reflectivity modulation can be further enhanced by incorporating Pockels material within the HCG structure, for example, in the gaps between features (etchings), or by using Pockels material to form features (with contacts on top).

[0060]

[0086] Figure 8 shows the use of an exemplary high-contrast grating (HCG) structure in wavefront modulation according to this disclosure. Referring to Figure 8, a high-contrast grating (HCG) 800 is shown.

[0061]

[0087] The HCG800 can be used with a vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) implemented under this disclosure, and the HCG is used in the proposed EML-based structure to facilitate and / or support the modulation function performed by the EML. Figure 8 shows an example of the application of the HCG, namely the use of the HCG800 in an EML-based structure acting as a wavefront modulator.

[0062]

[0088] In this regard, in the exemplary operation of such wavefront modulators, the HCG can be biased in groups, i.e., in sets of gratings in the HCG structure, as shown in Figure 8. Such biasing allows the beam to be deflected at discrete angles. The angles can be defined, for example, by the discrete geometry of the HCG structure. In some cases, the angle of deflection (or diffraction of the externally incident beam) can be tuned, as shown in Figure 8(810) and represented by Graph 820, which shows the normalized angular intensity distribution based on the use of the exemplary EML-based structure of this proposal.

[0063]

[0089] In the implementation based on this disclosure, wavefront modulation can be further enhanced by incorporating Pockels material into the HCG structure, for example, in the gaps between features (etchings), or by using Pockels material to form features (with contacts on top of them).

[0064]

[0090] Figure 9 illustrates the use of an exemplary vertical-cavity surface-emitting laser (VCSEL)-based field-absorption modulated laser (EML) incorporating a high-contrast grating (HCG) having a Pockels material as an intensity modulator, according to this disclosure. Referring to Figure 9, the high-contrast grating (HCG) 900 is shown.

[0065]

[0091] As described above, in some cases, a high-contrast grating can be used in a vertical-cavity surface-emitting laser (VCSEL) based field absorption modulation laser (EML) implemented under this disclosure, and the HCG900 is configured for such use in the EML-based structure of this proposal to facilitate and / or support the modulation function performed by the EML-based structure.

[0066]

[0092] As shown in Figure 9, the HCG900 can be arranged alternately (as shown in the plan view, i.e., the view looking down on the top of the structure) to incorporate two contacts, thereby forming an alternating interlocking gate grid. The HCG900 may also include Pockels material. In this regard, in the embodiment shown in Figure 9, the Pockels material is used to fill the gap between the two contacts. However, the present disclosure is not limited to such methods, and therefore the arrangement of the contacts and / or the Pockels material may be carried out in any suitable manner. For example, an alternative design in which the contacts are positioned on top of the Pockels material is shown in Figure 13.

[0067]

[0093] In an HCG, separate voltages (V1 and V2) can be applied to two contacts to produce a specific bias. In this regard, an alternating mating grid allows for the generation of electric fields through the Pockels material between two different grid elements (corresponding to the positions on the contacts where V1 and V2 are applied). The two contacts are not necessarily made of different materials; rather, the application of different voltages to the contacts generates different electric fields.

[0068]

[0094] The alternating interlocking bias grating generates a transverse electric field, as shown in Figure 9. This means that, due to the alternating arrangement, the direction of the electric field across the Pockels material can alternate (as shown in the figure). The alternating interlocking bias grating can also periodically change the refractive index (RI) of the entire HCG structure. In this regard, the RI can be changed within the grating by altering the electric field applied across the Pockels material. Since the RI affects the speed of light, changing the RI changes the phase of light passing through the grating.

[0069]

[0095] The use of Pockels material can further enhance performance. For example, low V Π To maintain this, Pockels material (and the corresponding Pockels effect) can be used together with resonant enhancement (from lattice features). In this regard, the Pockels effect itself may be too small to achieve the desired π phase shift, and therefore resonance may also be used to achieve the required optical field enhancement. Thus, the realization of the desired Pockels effect can be achieved not by increasing the voltage, but by providing resonant field enhancement. In other words, resonance from the lattice structure can be used to increase the intensity of the optical field, thereby enhancing the Pockels effect (without increasing the voltage applied to the lattice).

[0070]

[0096] As mentioned above, the use of HCG in the EML-based structure of this proposal is for lower target V Π This can enable the realization of (for example, << 5V). In this regard, if there is no cavity or resonant effect, the tilt angle (θ) can be determined using the following formula.

[0071]

number

[0072] Here, h is the height of the material and d is the lattice period. Without electric field enhancement, the effect may be too small.

[0097] For example, n=2, ΔV=5V, γ 33For 700 pm / V, h=1 μm, and d=100 nm, sin(Θ)=1.4e-2. To enhance by approximately 10 to 100 times, other means may be required, such as vertical DBR cavities, plasmon resonances from the grating, and high-contrast gratings (HCG). In this regard, HCG provides local ×10⁻⁶ 3 This can lead to electric field enhancement. Compared to optical microcavities, the electric field (E) used in HCG is similar, but the applied bias is much lower (due to the extremely small distance between electrodes). Nevertheless, in some cases, HCG can be combined with DBR cavities for even higher nonlinear effects.

[0073]

[0098] As shown in Figure 6, an EML-based structure incorporating the HCG900 (for example, used in VCSEL-EML devices) can function as an intensity (amplitude) modulator. However, EML-based structures can also be used to provide other functions, such as wavefront modulation and reflectance modulation.

[0074]

[0099] In one implementation, an EML-based structure with HCG incorporating Pockels material (e.g., used in VCSEL-EML devices) can be used to impart polarization rotation. In this context, lattice features are essentially linear polarizers and therefore selectively transmit light beams polarized in a particular direction (e.g., the x-direction). This structure can be configured to impart polarization rotation that can be used, for example, to block a beam. The use of such polarization rotation can be used in conjunction with, or instead of, the use of refractive index-related features.

[0075]

[0100] Figure 10 shows different processes for fabricating a vertical-cavity surface-emitting laser (VCSEL) based field absorption modulated laser (EML) incorporating a high-contrast grating (HCG) with Pockels material, according to the present disclosure. Referring to Figure 10, two different fabrication processes 1000 and 1010 for fabricating a VCSEL-EML having a high-contrast grating (HCG) structure with Pockels material are shown.

[0076]

[0101] In this regard, different methods (processes) can be used in the fabrication of optical devices (e.g., VCSELs) having EML-based structures incorporating HCGs with Pockels material, and this disclosure is not limited to any particular method or technique. The fabrication method may differ with respect to the deposition technique used when adding the Pockels material. The fabrication method may also be influenced by the design of the HCG (e.g., with respect to the arrangement of contacts used in the HCG). For example, when using alternating mating contacts, there may be several physical implementation forms available, as will be further detailed below, and the fabrication method may need to be adapted to take into account the use of such configurations. Thus, the fabrication method may differ in the manner in which the Pockels material is added to the particular grating (HCG) structure used.

[0077]

[0102] For example, the process can be "top-bottom" or "bottom-up" depending on the Pockels material deposition technique, as shown in Figure 10. In this regard, in process 1000, a Pockels material layer is first placed on an insulating layer. Next, the Pockels material layer is etched to form spaces for contacts, and then the contacts are added. In process 1010, the contacts are first added on an insulating layer, and the gaps between them are based on a predetermined alternating arrangement that includes gaps between the contacts. Next, a Pockels material layer is deposited or formed in the gaps between the contacts.

[0078]

[0103] In some cases, the process used to fabricate VCSEL-EMLs can be configured to meet predetermined criteria (e.g., dimensions in the final structure, such as a depth of approximately 250 nm and apertures in the range of 50 nm to 100 nm). Therefore, fabricating an HCG structure requires approximately 250 nm of additional and / or deposition on top, either to form the HCG only in specific areas (voids in a bottom-up process) or to form it across the entire surface, with some of the added layer being removed later (by etching stops).

[0079]

[0104] The implementation of Pockels materials, i.e., the addition of Pockels materials to a lattice structure, can be carried out in various ways, and this disclosure is not limited to any particular method; therefore, any suitable method can be used. For example, Pockels materials may be implemented at the wafer bonding level by processing (e.g., using BTO, Li.Nb., BaTiO3, etc.). Pockels materials may be implemented at or near the end of the process (e.g., using organic, BTO-based suspensions, etc.).

[0080]

[0105] Figure 11 shows defasing in an exemplary vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) incorporating a high-contrast grating (HCG) with Pockels material, according to the present disclosure. Referring to Figure 11, a VCSEL-EML1100 is shown incorporating an HCG structure with Pockels material in the gap between contacts. The VCSEL-EML1100 may be substantially similar to the VCSEL-EML900 described with respect to Figure 9.

[0081]

[0106] Figure 11 shows defaging in VCSELs such as the VCSEL-EML1100. In this context, defaging can occur as a result of the voltage difference between alternating mating gates, which can cause a periodic change in the refractive index (RI) within the structure. For example, the RI can be changed by controlling (setting and / or changing) the electric field applied across the Pockels material. Since the RI affects the speed of light, changing the RI changes the phase of light passing through the grating.

[0082]

[0107] In a VCSEL incorporating two contacts (e.g., VCSEL-EML1100), defasing can be performed by adjusting the voltage applied to the two contacts. In this regard, when the voltages are the same across the two contacts (i.e., V1=V2), the contacts are in phase, and therefore the interference is constructive in the vertical direction. On the other hand, when the voltages are not the same (i.e., V1≠V2), a periodic change in refractive index can be produced, resulting in canceling interference in the vertical direction, and thus defasing of the contacts (gate).

[0083]

[0108] Figure 12 illustrates the use of an exemplary vertical-cavity surface-emitting laser (VCSEL)-based field-absorption modulated laser (EML) incorporating a high-contrast grating (HCG) with Pockels material, as described in this disclosure, in wavefront modulation. Referring to Figure 12, a VCSEL-EML1200 is shown incorporating an HCG structure with Pockels material in the gap between contacts.

[0084]

[0109] The VCSEL-EML1200 can be substantially similar to the VCSEL-EML900 described with respect to Figure 9. As shown in Figure 12, the VCSEL-EML1200 can function as a wavefront modulator. In this regard, the refractive index (RI) can be changed based on changing the electric field applied to different contacts across the Pockels material. As mentioned above, the RI affects the speed of light, and therefore changing the RI changes the phase of light passing through the grating. Thus, the contacts become in phase when the Pockels material receives the same voltage, as shown in Figure 12, and out of phase when the voltages are different.

[0085]

[0110] In various implementations, several subwavelength gratings can share the same bias. This allows the outgoing wave to remain within the optical cone and also causes defasing between groups or gratings. However, using Pockels-based EMLs (such as the VCSEL-EML1200 in Figure 12) as wavefront modulators may be limited to certain types of Pockels materials. For example, only Pockels materials with a strong r42 can be used.

[0086]

[0111] Figure 13 illustrates the use of an exemplary vertical-cavity surface-emitting laser (VCSEL)-based field-absorption modulated laser (EML) incorporating a high-contrast grating (HCG) with contacts on a Pockels material, as described in this disclosure, in wavefront modulation. Referring to Figure 13, a VCSEL-EML1300 incorporating an HCG structure with Pockels material is shown.

[0087]

[0112] The VCSEL-EML1300 may be substantially similar to the VCSEL-EML described with respect to Figure 9. However, the VCSEL-EML1300 may differ in that the contacts are positioned on a Pockels material, as shown in Figure 13. As shown in Figure 13, the VCSEL-EML1300 can function as a wavefront modulator. In this regard, when used as a wavefront modulator, the VCSEL-EML1300 can operate substantially similarly to the VCSEL-EML1200 described with respect to Figure 12. Specifically, the refractive index (RI) in the VCSEL-EML1300 can also be changed by changing the electric field applied across the Pockels material, in this case the electric field is applied from the substrate through the Pockels material to the contacts on the Pockels material. As mentioned above, changing the RI changes the phase of the light passing through the grating, and as shown in Figure 13, the contacts become in phase when the same voltage is applied, and out of phase when the voltages are different.

[0088]

[0113] Figure 14 shows the processing of incident external light in an exemplary vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) having a high-contrast grating (HCG) structure incorporating Pockels material, according to the present disclosure. Referring to Figure 14, a VCSEL-EML1400 is shown incorporating an HCG structure with Pockels material in the gap between contacts.

[0089]

[0114] The VCSEL-EML1400 may be substantially similar to the VCSEL-EML900 described with respect to Figure 9. However, the high-contrast grating (HCG) structure in the VCSEL-EML1400 may include different materials such as aluminum gallium arsenide (AlGaAs). Such designs (techniques) may have various advantages, including being small, ultrafast, low-loss, and enabling wavelength tuning by the grating rather than the material (e.g., low-density wavelength division multiplexing (CWDM) or high-density wavelength division multiplexing (DWDM) on the same array). The use of an external laser source (e.g., a comb laser) may enable high-temperature / low-power consumption data transmission.

[0090]

[0115] Figure 14 shows the processing of the incident beam (light) projected onto the VCSEL-EML1400 from the outside (not from the bottom via the substrate). In connection with this, due to defasing, the absorption resonance of the HCG in the VCSEL-EML1400 can be finely tuned, thereby causing a change in reflectivity. Therefore, if the voltage applied to the contacts is different, the contacts will be out of phase, and as a result, the incident light will be reflected at a specific angle, as shown in Figure 14.

[0091]

[0116] Figure 15 illustrates the use of an exemplary vertical-cavity surface-emitting laser (VCSEL)-based field absorption modulated laser (EML) incorporating a high-contrast grating (HCG) with Pockels material in polarization modulation, as described in this disclosure. Referring to Figure 15, the VCSEL-EML1500 is shown.

[0092]

[0117] The VCSEL-EML1500 may be substantially similar to the VCSEL-EML described with respect to Figure 9. However, the VCSEL-EML1500 may differ in that contacts (e.g., metal contacts) are placed on the Pockels material, as shown in Figure 15. As shown in Figure 15, the VCSEL-EML1500 can function as a polarization modulator. Nevertheless, the polarization modulation described herein is not limited to this particular implementation corresponding to the VCSEL-EML1500, and such polarization modulation is applicable to and / or can be provided by any of the EML-based structures of the present proposal disclosed herein.

[0093]

[0118] In this regard, HCG may have strong birefringence between transverse electric field (TE) mode and transverse magnetic field (TM) mode. Therefore, the design and / or implementation of the device can be made to take advantage of such properties when providing polarization modulation via the proposed EML-based structure (incorporating Pockels material). This can be done in any of the implementation forms disclosed herein. Polarization modulation can be achieved, for example, by utilizing the alternating mating contact arrangement in the proposed EML structure. Therefore, the same principles and techniques used in wavefront modulation can be used in polarization modulation, for example, by connecting all teeth of the HCG to the same bias source. Polarization modulation can be considered a subset of amplitude modulation schemes.

[0094]

[0119] For example, polarization modulation can be achieved by modulating within the HCG to enable or suppress modes. In this regard, the HCG characteristics may change specularly near the mode cutoff, as shown in Graphs 1510 and 1520, which show abrupt changes for TE reflectance and abrupt changes for TM reflectance, and overlapping regions. In this regard, there may be strong sensitivity of both polarizations to refractive index changes at overlapping transition frequencies (e.g., TM6 / TE6). The EML structure can be modified to optimize polarization modulation. For example, an appropriate thickness of the HCG may allow for the identification of spots where TE reflectance increases as TM reflectance decreases (or vice versa) when the bias is changed.

[0095]

[0120] Figure 16 shows exemplary variations of high-contrast grid (HCG) structures having Pockels material according to this disclosure. Referring to Figure 16, various variations of HCG having Pockels material are shown. Specifically, Figure 16 shows HCG1600, 1610, 1620, 1630, 1640 and 1650. In this regard, HCG1600 represents the basic implementation form, and HCG1610, 1620, 1630, 1640 and 1650 represent alternative variations of the basic implementation form.

[0096]

[0121] Modifications of the basic implementation form (HCG1600) may include dimerization of the HCG. In connection with this, such modifications may enable lower resonant frequencies. Such modifications can be of different flavors. For example, this can be done by changing geometric parameters such as the width of high-refractive-index or low-refractive-index materials, as shown in HCG1640 (modification 1), by changing the material of every other tooth, as shown in HCG1640 (modification 2), or by connecting every other tooth, as shown in HCG1640 (modification 3).

[0097]

[0122] The HCG pattern can also be spatially varied, for example, based on changes in the pattern in the x or y direction. This may include slow spatial shifts of resonance, e.g., fluctuations of less than 1% across lambda, as shown in HCG1640(modification 4), or abrupt shifts of HCG parameters, e.g., as shown in HCG1640(modification 5), where one or more parameters have a 1% fluctuation between one iteration of the motif and the next, but the geometry remains stable over more than 10 lambdas.

[0098]

[0123] Figure 17 shows a first exemplary implementation of an alternating mating field absorption modulated laser (EML)-based structure according to the present disclosure. Referring to Figure 17, an EML-based structure 1700 is shown. Specifically, Figure 17 shows a top view 1710 and a side view 1720 corresponding to a specific cross section (line) of the structure.

[0099]

[0124] As shown in the side view 1720, the EML-based structure 1700 includes a general-purpose vertical light-emitting layer, followed (in the z direction) by an insulating layer, and then a high-contrast grating (HCG) containing two contacts (V1 and V2) with a metal-containing semiconductor material (e.g., doped semiconductor) on top, with the Pockels material positioned between the contacts. The contacts are (optionally) covered by a capping layer (not shown in the top view 1710).

[0100]

[0125] The general-purpose vertical emission layer may include any suitable structure that can be configured to emit a laser in a vertical direction. In one exemplary implementation, the general-purpose vertical emission layer may include a substrate, which may optionally be sandwiched between two vertical emission epistack layers. In this regard, the epistack may include a VCSEL or PCSEL (or a second-, third-, ..., n-th-order distributed feedback laser (DFB)). The substrate may include suitable materials such as gallium arsenide (GaAs), gallium nitride (GaN), indium phosphide (InP), silicon (Si), and silicon carbide (SiC).

[0101]

[0126] The insulating layer is made of a semiconductor (doped or undoped current-blocking layer) or a ceramic (aluminum oxide AlO x It may contain silicon nitride (SiN), silicon oxide (SiO2), etc. Pockels materials may contain materials with a large r33.

[0102]

[0127] The materials used in the contacts may include gold (Au), silver (Ag), copper (Cu), or transparent conductive materials (such as indium tin oxide (ITO)).

[0128] The Pockels material used in this implementation may need to have a low refractive index (e.g., IR < 2), such as a polymer. As shown in top view 1710, the exemplary implementation shown in Figure 17 may have partial or complete coating of doped semiconductor (contacts) in the y direction. The balance between optical loss and RF electrical loss depends on the specific application. As mentioned above, the vertical emission epistack layer may or may not be included between or under the substrate and the EML.

[0103]

[0129] Figure 18 shows a second exemplary implementation of an alternating mating field absorption modulated laser (EML)-based structure according to the present disclosure. Referring to Figure 18, an EML-based structure 1800 is shown. Specifically, Figure 18 shows a top view 1810 and a side view 1820 corresponding to a specific cross section (line) of the structure.

[0104]

[0130] As shown in the side view 1820, the EML-based structure 1800 includes a general-purpose vertical light-emitting layer, followed thereafter (in the z direction) by an insulating layer, and then a high-contrast grating (HCG) containing two contacts (V1 and V2), with Pockels material positioned between the contacts. The contacts are (optionally) covered by a capping layer (not shown in the top view 1810).

[0105]

[0131] The general-purpose vertical emission layer may include any suitable structure that can be configured to emit a laser in a vertical direction. In one exemplary implementation, the general-purpose vertical emission layer may include a substrate, which may optionally be sandwiched between two vertical emission epistack layers. The epistack may include a VCSEL or PCSEL (or a second-, third-, ..., n-th order distributed feedback laser (DFB)). The substrate may include suitable materials such as gallium arsenide (GaAs), gallium nitride (GaN), indium phosphide (InP), silicon (Si), and silicon carbide (SiC).

[0106]

[0132] The insulating layer may include a semiconductor (doped or undoped current-blocking layer) or a ceramic (such as aluminum oxide (AlOx), silicon nitride (SiN), or silicon oxide (SiO2)).

[0107]

[0133] Pockels materials may include materials with a large r33. In the 1800 configuration, the contacts (V1 and V2) may include transparent metals with a low refractive index n<1.6 (e.g., silver nanowires (AgNW), CN, hybrids, etc.).

[0108]

[0134] The Pockels material used in this implementation may need to have a high refractive index > 2 (e.g., SBN60, BaTi03, etc.). Also, as with the previous implementation, it may or may not include a vertically emitting epistack layer placed between or beneath the substrate and the EML.

[0109]

[0135] Figure 19 shows a third exemplary implementation of the alternating mating field absorption modulated laser (EML)-based structure according to the present disclosure. Referring to Figure 19, the EML-based structure 1900 is shown. Specifically, Figure 19 shows a top view 1910 and a side view 1920 corresponding to a specific cross section (line) within the structure of the EML-based structure 1900.

[0110]

[0136] As shown in the side view 1920, the EML-based structure 1900 includes a general-purpose vertical light-emitting layer, followed thereafter (in the z direction) by a transverse contact layer above it, and then a high-contrast grating (HCG) containing two contacts (V1 and V2) with a metal-containing semiconductor (e.g., doped semiconductor) material on top, where the Pockels material is placed between the contact metals on top of the Pockels material, and the undoped semiconductor material is placed between the contacts, specifically between the Pockels materials as shown in the figure. The contacts are (optionally) covered by a capping layer (not shown in the top view 1910).

[0111]

[0137] The general-purpose vertical emission layer may include any suitable structure that can be configured to emit a laser in a vertical direction. In one exemplary implementation, the general-purpose vertical emission layer may include a substrate, which may optionally be sandwiched between two vertical emission epistack layers. The epistack may include a VCSEL or PCSEL (or a second-, third-, ..., n-th order distributed feedback laser (DFB)). The substrate may include suitable materials such as gallium arsenide (GaAs), gallium nitride (GaN), indium phosphide (InP), silicon (Si), and silicon carbide (SiC).

[0112]

[0138] The lateral contact layer may contain a transparent conductive material. The Pockels material may contain large r42, r63, and other Pockels materials. The contact material may contain gold (Au), silver (Ag), copper (Cu), or a transparent conductive material (e.g., indium tin oxide (ITO)).

[0113]

[0139] The Pockels material used in this configuration may need to have a low refractive index (e.g., IR<2), such as KDP or polymer. In some cases, the lateral contact layer may be biased in this configuration, resulting in three different biases. Nevertheless, in many cases, the bias applied to the lateral contact layer may be the same as the bias applied to one of the contacts (e.g., V3=V2=0). Also, as in the previous configuration, the vertically emitting epistack layer may or may not be included between or under the substrate and the EML.

[0114]

[0140] Figure 20 shows fourth and fifth illustrative implementations of the alternating mating field absorption modulated laser (EML)-based structures according to the present disclosure. Referring to Figure 20, EML-based structures 2000 and 2010 (each viewed from the side) are shown.

[0115]

[0141] As shown in Figure 20, each of the EML-based structures 2000 and 2010 includes a general-purpose vertical light-emitting layer, followed (in the z direction) by a transverse contact layer above it, and then a high-contrast grating (HCG) containing two contacts (V1 and V2) with a metal-containing semiconductor (e.g., doped semiconductor) material on top of the Pockels material, with the contact metal on top of the Pockels material, and as shown in the figure, an undoped semiconductor material is placed between the contacts, specifically between the Pockels materials. The contacts are (optionally) covered by a cap layer (not shown in the top view figure 2010).

[0116]

[0142] The general-purpose vertical emission layer may include any suitable structure that can be configured to emit a laser in a vertical direction. In one exemplary implementation, the general-purpose vertical emission layer may include a substrate, and the substrate may include an emission epistack layer on any face of the substrate. The epistack may include a VCSEL or PCSEL (or a second-, third-, ..., n-th order distributed feedback laser (DFB)). The substrate may include suitable materials such as gallium arsenide (GaAs), gallium nitride (GaN), indium phosphide (InP), silicon (Si), and silicon carbide (SiC).

[0117]

[0143] The lateral contact layer may contain a transparent conductive material. The Pockels material may contain large r42, r63, and other Pockels materials. The contact material may contain gold (Au), silver (Ag), copper (Cu), or a transparent conductive material (e.g., indium tin oxide (ITO)).

[0118]

[0144] The EML-based structures 2000 and 2010 may be substantially similar to the EML-based structure 1900 described with respect to Figure 19. However, the EML-based structures 2000 and 2010 differ from each other (and from the EML-based structure 1900) in that there are some variations in the HCG in each of these structures. Specifically, the HCG in the EML-based structure 2000 differs from that in the EML-based structure 2000 in that the contacts (V1 and V2) are of different sizes (for example, V1 is larger than V2 as shown in Figure 20), whereas in the EML-based structure 1900 these contacts are of the same size.

[0119]

[0145] In the case of EML-based structure 2010, the difference is that the HCG used incorporates a capping layer material between the contacts (in addition to the undoped semiconductor material), as shown in Figure 20. Also, EML-based structures 2000 and 2010 differ from EML-based structure 1900 in that they have different biases (e.g., V1=V2≠V3). However, these two implementation configurations can exhibit similar physical effects to the alternating-fitting EML-based implementation configuration because the effective refractive index varies in a different manner in each dimer. In this regard, as shown in Figure 20, a similar effect can be obtained by filling only about half of the HCG globe with Pockels material, for example.

[0120]

[0146] Figure 21 shows a sixth exemplary implementation of the alternating mating field absorption modulated laser (EML)-based structure according to this disclosure.

[0147] Referring to Figure 21, the EML-based structure 2100 is shown. Specifically, Figure 21 shows a top view 2110 of the EML-based structure 2100 and a side view 2120 corresponding to a specific cross-section (line) of the structure.

[0121]

[0148] As shown in the side view 2120, the EML-based structure 2100 includes a general-purpose vertical light-emitting layer, followed (in the z direction) by a lateral contact layer above it, and then a high-contrast grating (HCG) containing two contacts (V1 and V2) made of a semiconductor (e.g., doped semiconductor) material, with a metal on top of the Pockels material. The contacts are (optionally) covered by a capping layer (not shown in the top view 2110). As shown in the figure, the capping material is also placed between the contacts, specifically between their Pockels materials.

[0122]

[0149] The general-purpose vertical emission layer may include any suitable structure that can be configured to emit a laser in a vertical direction. In one exemplary implementation, the general-purpose vertical emission layer may include a substrate, and the substrate may include an emission epistack layer on any of its faces. The epistack may include a VCSEL or PCSEL (or a second-, third-, ..., n-th order distributed feedback laser (DFB)). The substrate may include suitable materials such as gallium arsenide (GaAs), gallium nitride (GaN), indium phosphide (InP), silicon (Si), and silicon carbide (SiC).

[0123]

[0150] The lateral contact layer may contain a transparent conductive material. The Pockels material may contain large r42, r63, and other Pockels materials. The contact material may contain gold (Au), silver (Ag), copper (Cu), or a transparent conductive material (e.g., indium tin oxide (ITO)).

[0124]

[0151] Similar to the EML-based structure 1900, the Pockels material used in this implementation may need to have a low refractive index (e.g., IR<2), such as KDP or polymer, and in some cases the lateral contact layer may be biased, resulting in three different biases (however, in many cases the bias applied to the lateral contact layer may be the same as the bias applied to one of the contacts (e.g., V3=V2=0)). Also, as with the previous implementations, the vertical emitting epistack layer may or may not be included between or under the substrate and the EML. Although not shown, alternative implementations may be used by modifying the HCG structure, similar to the EML-based structure 1900, as described with respect to Figure 20, in which the HCG is modified in the EML-based structures 2000 and 2010 compared to the EML-based structure 1900.

[0125]

[0152] Figure 22 shows an exemplary vertical-cavity surface-emitting laser (VCSEL) based field-absorption modulated laser (EML) incorporating a high-contrast grating (HCG) having a Pockels material and a gate dielectric, according to the present disclosure. Referring to Figure 22, the VCSEL2200 is shown.

[0126]

[0153] The VCSEL2200 has a lattice structure (e.g., HCG) on which Pockels material fills the gaps within the lattice structure, and may include a VCSEL epitaxial layer (with no or only a few upper pairs) having contacts on the surface of the lattice structure. Some of the contacts may incorporate a dielectric (for gates). Thus, some of the contacts (e.g., contacts without dielectric) can form and / or function as grounds, and the remaining contacts (e.g., contacts with dielectric) can function as RF elements in the VCSEL2200.

[0127]

[0154] Figure 23 shows exemplary vertical-cavity surface-emitting laser (VCSEL) based optical devices, one of which incorporates an electric field absorption modulated laser (EML) based design. Figure 23 shows optical devices 2300 and 2310, both of which are VCSEL-based devices. In this regard, Figure 23 shows top views of optical devices 2300 and 2310.

[0128]

[0155] As shown in Figure 23, the optical device 2300 includes a VCSEL-based structure on a substrate etching (for example, as described in relation to Figure 2), and has contacts (wirings) on the VCSEL structure. The optical device 2300 has RF as an input to the contact wiring at one end. in The application of a signal and the corresponding RF as an output at the other end of the contact wiring. out / dump It can be configured to emit light (e.g., a laser) in response to a signal output.

[0129]

[0156] Optical device 2310 corresponds to an exemplary modification of optical device 2300 in an exemplary implementation form based on the present disclosure. In this regard, optical device 2310 may be substantially similar to optical device 2300, but modifications may be incorporated to enable the modulation functions and / or characteristics described herein. For example, optical device 2310 may incorporate modifications to the contact wiring, such as using a plurality of separate contact wirings as shown in Figure 23, to form an alternating mating grid-based design that enables bias application to the contacts, as described above, by grounding a portion of the contact wiring (e.g., applying a ground signal) as shown in Figure 23.

[0130]

[0157] As used herein, “and / or” means any one or more of the items in the enumeration connected by “and / or.” For example, “x and / or y” means any element of the three-element set {(x), (y), (x, y)}. In other words, “x and / or y” means “one or both of x and y.” As another example, “x, y and / or z” means any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, “x, y and / or z” means “one or more of x, y and z.” As used herein, the term “exemplary” means an unrestricted example, case, or illustration. As used herein, the terms “for example” and “eg” are the beginning of a statement of one or more unrestricted examples, cases, or illustrations.

[0131]

[0158] As used herein, the terms “circuit” and “circuit network” refer to physical electronic components (e.g., hardware) and any software and / or firmware ("code") that can constitute hardware, be executable by hardware, and / or otherwise be associated with hardware. As used herein, certain processors and memories (e.g., volatile or non-volatile memory devices, general-purpose computer-readable media, etc.) may constitute a first “circuit” if they execute a first one or more lines of code, and a second “circuit” if they execute a second one or more lines of code. Furthermore, circuits may include analog and / or digital circuits. Such a circuit network may operate with analog and / or digital signals, for example. It should be understood that circuits may reside in a single device or chip, on a single motherboard, in a single chassis, in multiple enclosures in a single geographical location, in multiple enclosures distributed across multiple geographical locations, and so on. Similarly, the term “module” may refer, for example, to a physical electronic component (e.g., hardware) and any software and / or firmware ("code") that can constitute the hardware, is executable by the hardware, and / or can otherwise be associated with the hardware.

[0132]

[0159] As used herein, a network or module is “operable” to perform its function when it contains the necessary hardware and code (if any) to perform that function, regardless of whether the execution of that function is disabled or enabled (for example, by user-configurable settings, factory settings, etc.).

[0133]

[0160] Other embodiments of the present invention can provide a non-transient computer-readable medium and / or storage medium, and / or a non-transient machine-readable medium and / or storage medium, which stores machine code and / or a computer program having at least one code segment executable by a machine and / or computer, thereby causing a machine and / or computer to perform the processes described herein.

[0134]

[0161] Various embodiments of the present invention include all features that enable the implementation of the methods described herein and can be incorporated into a computer program product that, when loaded into a computer system, can carry out those methods. In this context, a computer program means any expression in any language, code or notation of a set of instructions intended to cause a system having information processing capabilities to perform a particular function, either directly or after either or both of the following: a) conversion into another language, code or notation, or b) reproduction in a different concrete form.

[0135]

[0162] While the present method and / or system has been described with reference to a specific implementation, those skilled in the art will see that various modifications can be made and equivalents can be substituted without departing from the scope of the present method and / or system. Furthermore, many modifications can be made to adapt the teachings of this disclosure to specific circumstances or materials without departing from the scope of this disclosure. Thus, the present method and / or system is not limited to the specific implementation disclosed, and is intended to include all implementations included in the appended claims.

Claims

1. Light source and A modulator relating to the light source and An optical device including, The modulator includes a grounding substrate and a grid structure including a plurality of grid lines. Each of the plurality of grid lines includes a contact and a Pockels material between the contact and the grounding substrate. Optical devices.

2. The optical device according to Claim 1, A voltage is applied to each of the plurality of grid lines through the contacts included in the grid line. The plurality of grid lines include a plurality of adjacent grid lines to which a first voltage is applied and a plurality of adjacent grid lines to which a second voltage is applied. The first voltage and the second voltage are configured to be controlled independently. Optical devices.

3. An optical device according to claim 1, wherein the modulator is operable to reflect back an optical signal having an appropriate wavelength from the light source to the light source when a voltage is applied to the contact.

4. An optical device according to claim 1, wherein the modulator is operable to deflect an optical signal received from a light source at an angle adjustable from perpendicular to the surface of the modulator, based on a voltage applied to the contact.

5. An optical device according to claim 1, wherein the plurality of grid lines include a subwavelength dimension in at least one dimension.

6. An optical device according to claim 1, wherein the light source includes a vertical cavity surface-emitting laser (VCSEL), a photonic crystal surface-emitting laser (PCSEL), or a higher-order distributed feedback (DFB) laser.

7. An optical device according to claim 1, wherein the refractive index associated with the modulator is composed of one or more of the width of the grid lines, the spacing of the grid lines, and the periodicity of the grid lines.

8. An optical device according to claim 7, wherein the modulator is configured to impart phase modulation to an incident beam or incident wave coupled to the modulator based on an adjustment to the refractive index (RI) associated with the modulator.

9. An optical device according to claim 1, wherein the modulator is configured to impart polarization modulation to an incident beam or incident wave coupled to the modulator.

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