Achieving both high thermal stability and high electro-optical (EO) activity has traditionally been challenging in organic EO (OEO) materials. The highest combination of thermal stability and EO performance has previously been obtained with HLD1/HLD2, which is a cross-linkable, polymer-free binary OEO material capable of achieving an EO coefficient (r(33)) of up to 450 pm/V when not cross-linked and >250 pm/V (n(3)r(33) > 2000 pm/V) at 1310 nm when cross-linked to a glass transition temperature (T-g) similar to 175 degrees C. Herein, we report the design, synthesis, and evaluation of a cross-linkable chromophore system based on two higher hyperpolarizability chromophores BAH-X1 and BAH-X2, with complementary cross-linkable side chains. BAHX has similar to 2 times the hyperpolarizability of HLD & horbar;based on hyper-Rayleigh scattering measurements & horbar;and similar to 2 times the EO performance (maximum r(33) up to 1100 pm/V when not cross-linked and >650 pm/V, n(3)r(33) > 4500 pm/V, when cross-linked to T-g similar to 150 degrees C). Long-term (>2000 h) thermal stability of EO activity has been demonstrated at 85 degrees C under nitrogen. This high EO activity has been translated to excellent device performance in a plasmonic-organic hybrid phase modulator utilizing 2:1 BAHX, demonstrating a push-pull Mach-Zehnder modulator equivalent V pi L = 38 V mu m at 1550 nm.

We demonstrate open-eye 224G PAM4 transmission in a 1.6T-DR8 PIC implementing low-Vπ silicon-organic hybrid modulators (VπL < 0.5 V-mm) with >80 3 dB GHz bandwidth and a variant capable of 400G/λ (> 110 GHz) for 3.2T-DR8. Both PIC variants use commercial crosslinkable organic electro- optic materials.

We demonstrate the first silicon-organic hybrid electro-optic modulator relying on a long-term-stable thermally crosslinked organic electro-optic material. After more than 2200 hours of high-temper-ature storage at 120°C, the device still operates at line rates of 200 Gbit/s PAM4 and 100 Gbit/s OOK.

The growth of integrated photonics has driven the need for efficient, high-bandwidth electrical-to-optical (EO) signal conversion over a broad range of frequencies (MHz–THz), together with efficient, high bandwidth photodetection. Efficient signal conversion is needed for applications including fiber/wireless telecom, data centers, sensing/imaging, metrology/spectroscopy, autonomous vehicle platforms, etc., as well as cryogenic supercomputing/quantum computing. Diverse applications require the ability to function over a wide range of environmental conditions (e.g., temperatures from <4 to >400 K). Active photonic device footprints are being scaled toward nanoscopic dimensions for size compatibility with electronic elements. Nanophotonic devices increase optical and RF field confinement via small feature sizes, increasing field intensities by many orders of magnitude, enabling high-performance Pockels effect materials to be ultimately utilized to their maximum potential (e.g., in-device voltage-length performance ≤0.005 V mm). Organic materials have recently exhibited significant improvements in performance driven by theory-guided design, with realized macroscopic electro-optic activity (r33) exceeding 1000 pm/V at telecom wavelengths. Hybrid organic/semiconductor nanophotonic integration has propelled the development of new organic synthesis, processing, and design methodologies to capture this high performance and has improved understanding of the spatial distribution of the order of poled materials under confinement and the effects of metal/semiconductor-organic interfaces on device performance. Covalent coupling, whether from in situ crosslinking or sequential synthesis, also provides a thermally and photochemically stable alternative to thermoplastic EO polymers. The alternative processing techniques will reduce the attenuation of r33 values observed in silicon organic hybrid and plasmonic organic hybrid devices arising from chromophore-electrode electrostatic interactions and material conductance at poling temperatures. The focus of this perspective is on materials, with an emphasis on the need to consider the interrelationship between hybrid device architectures and materials.

Hybrid organic electro-optic (OEO) modulators consist of aligned OEO chromophores confined in a metal or semiconductor slot waveguide, enabling optical fields to be tightly confined within the OEO material. The combination of tight confinement with the high electro-optic (EO) performance of state-of-the art OEO materials enables extraordinary EO modulation performance in silicon-organic hybrid (SOH) and plasmonic-organic hybrid (POH) device architectures. Recent records in POH devices include bandwidths < 500 GHz and energy efficiency < 100 aJ/bit. To enable commercial applications of these materials and devices, however, the materials integration processes must be finely tuned to afford excellent EO activity and long-term stability under demanding conditions, both during manufacture and operation. The conceptually simple design of POH devices affords a useful platform for process optimization, while the intense optical confinement provides an ideal environment to examine the photochemical stability of OEO materials in hybrid modulators. We have performed process optimization to obtain good EO performance with commercial and developmental OEO materials in POH devices, and examined the long-term operational and shelf storage stability of such devices under a variety of conditions relevant to Telecordia GR-468-CORE standards. We analyze the results of these studies and discuss their implications for commercial applications, including manufacturing, encapsulation requirements, and expected operational lifetimes.

The development of silicon-organic hybrid (SOH) and plasmonic-organic hybrid (POH) electro-optic modulators in the 2010s has enabled the large electro-optic (EO) performance of organic chromophores to be leveraged for high-performance photonic components capable of integration with CMOS electronics. Recent improvements in theory-aided design and materials performance have enabled large increases in both electro-optic performance and materials stability. We report on the implications of these developments for hybrid device performance, manufacturability, processing, and packaging, as well as potential new directions for increasingly scalable fabrication of hybrid electro-optic devices for classical and quantum communications and computing applications.

The first transparent Optical-subTHz-Optical link providing record-high line-rates of 240 and 190 Gbit/s over distances from 5 to 115 m was recently demonstrated. The link has been based on a direct data-conversion from optical to subTHz using a > 500 GHz plasmonic Mach-Zehnder modulator. We discuss the potential of plasmonic devices in subTHz wireless links to efficiently bridge optical fiber networks.

We demonstrate cryogenic operation of a silicon-organic hybrid (SOH) Mach-Zehnder modulator. The device is based on a dedicated material formulation and allows for 50 Gbit/s on-off-keying (OOK) at 4 K - a record-high line rate generated by an MZM at this temperature.

Hybrid organic electro-optic (OEO) modulators consist of a layer of ordered organic chromophores confined between layers of metals or semiconductors, enabling optical fields to be tightly confined within the OEO material. The combination of tight confinement with the high electro-optic (EO) performance of state-of-the-art OEO materials enables extraordinary EO modulation performance in silicon-organic hybrid (SOH) and plasmonic-organic hybrid (POH) device architectures. Recent records in POH devices include bandwidths >500 GHz and energy efficiency <100 aJ/bit. To enable commercial applications of these materials and devices, however, they must withstand demanding thermal and environmental conditions, both during manufacture and operation. To address these concerns, we examined the long-term thermal and environmental shelf storage stability of state-of-the-art commercial and developmental OEO materials under a variety of conditions relevant to Telecordia GR-468-CORE standards. We examined the shelf storage of poled OEO materials under a nitrogen atmosphere at a range of temperatures from 85 ˚C up to 150 ˚C to understand the kinetics of the thermally activated de-poling of the OEO materials. We also examined the shelf storage of OEO materials under a variety of atmospheres, including the aggressive 85 ˚C and 85% relative humidity damp heat condition, to understand the relative sensitivities of the materials to water and oxygen at different temperatures. We analyze the results of these studies and discuss their implications for commercial application of these materials and devices, including manufacturing, encapsulation requirements, and expected operational lifetimes.

A transparent Optical-subTHz-Optical link providing record-high single line rates of 240 Gbit/s and 192 Gbit/s on a single optical carrier over distances from 5 to 115 m is demonstrated.Besides a direct mapping of the optical to a 230 GHz subTHz-carrier frequency by means of a uni-traveling carrier (UTC) photodiode, we demonstrate direct conversion of data from the subTHz domain back to the optical domain by a plasmonic modulator.It is shown that the subTHz-to-optical upconversion can even be performed at good quality without any electrical amplifiers.Finally, at the receiver, the local oscillator is employed to directly map the optical signal back to the electrical baseband within a coherent receiver.

We design and fabricate an electro optical spatial light modulator based on a Fabry Perot resonator utilizing a fast switchable integrated organic polymer layer, where the phase response can be tuned on a subwavelength scale.

Organic electro-optic (EO) materials incorporated into silicon-organic hybrid and plasmonic-organic hybrid devices have enabled new records in EO modulation performance. We report a new series of nonlinear optical chromophores engineered by theory-guided design, utilizing bis(4-dialkylaminophenyl)heteroarylamino donor moieties to greatly enhance molecular hyperpolarizabilities. Hyperpolarizabilities predicted using density functional theory were validated by hyper-Rayleigh scattering measurements, showing strong prediction/experiment agreement and >2-fold advancement in static hyperpolarizability over the best prior chromophores. Electric field poled thin films of these chromophores showed significantly enhanced EO coefficients (r(33)) and poling efficiencies (r(33)/E-p) at low chromophore concentrations compared with state-of-the-art chromophores such as JRD1. The highest performing blend, containing just 10 wt% of the novel chromophore BTP7, showed a 12-fold enhancement in poling efficiency per unit concentration vs.JRD1. Our results suggest that further improvement in chromophore hyperpolarizability is feasible without unacceptable tradeoffs with optical loss or stability.

Hybrid organic electro-optic (OEO) devices consist of a layer of ordered organic chromophores confined between layers of metals or semiconductors, enabling optical fields to be tightly confined within the OEO material. The combination of tight confinement with the high electro-optic (EO) performance of state-of-the art OEO materials enables exceptional electro-optic switching performance in silicon-organic hybrid (SOH) and plasmonic-organic hybrid (POH) device architectures. Recent records in POH devices include bandwidths < 500 GHz and energy efficiency < 100 aJ/bit. However, optimization of device performance requires both understanding and improving the degree to which chromophores can be acentrically ordered near a metal or semiconductor interface. Applying bulk and/or isotropic models of OEO materials to nanophotonic device architectures often lead to overly optimistic translation of materials performance to device performance. Prior work has identified influences of high centrosymmetric order (birefringence), altered relations between acentric and centrosymmetric order (dimensionality), and surface electrostatics on chromophore ordering. We combine these models into a representation that can be used to understand the influences of these phenomena on device performance, how some prior OEO materials exhibited unusually high performance under confinement, how ordering close to surfaces may be improved, and implications for future electro-optic device design.

We present reliability studies of plasmonic-organic-hybrid modulators for high-speed optical communications. By exclusion of oxygen and water, demanding thermal environments and high optical power levels can be tolerated.

High performance organic electro‐optic (OEO) materials enable ultrahigh bandwidth, small footprint, and extremely low drive voltage in silicon‐organic hybrid and plasmonic‐organic hybrid photonic devices. However, practical OEO materials under device‐relevant conditions are generally limited to performance of ≈300 pm V−1 (10× the EO response of lithium niobate). By means of theory‐guided design, a new series of OEO chromophores is demonstrated, based on strong bis(4‐dialkylaminophenyl)phenylamino electron donating groups, capable of EO coefficients (r33) in excess of 1000 pm V−1. Density functional theory modeling and hyper‐Rayleigh scattering measurements are performed and confirm the large improvement in hyperpolarizability due to the stronger donor. The EO performance of the exemplar chromophore in the series, BAY1, is evaluated neat and at various concentrations in polymer host and shows a nearly linear increase in r33 and poling efficiency (r33/Ep, Ep is poling field) with increasing chromophore concentration. 25 wt% BAY1/polymer composite shows a higher poling efficiency (3.9 ± 0.1 nm2 V−2) than state‐of‐the‐art neat chromophores. Using a high‐ε charge blocking layer with BAY1, a record‐high r33 (1100 ± 100 pm V−1) and poling efficiency (17.8 ± 0.8 nm2 V−2) at 1310 nm are achieved. This is the first reported OEO material with electro‐optic response larger than thin‐film barium titanate.

This study demonstrates enhancement of in-device electro-optic activity via a series of theory-inspired organic electro-optic (OEO) chromophores based on strong (diarylamino)phenyl electron donating moieties. These chromophores are tuned to minimize trade-offs between molecular hyperpolarizability and optical loss. Hyper-Rayleigh scattering (HRS) measurements demonstrate that these chromophores, herein described as BAH, show >2-fold improvement in β versus standard chromophores such as JRD1, and approach that of the recent BTP and BAY chromophore families. Electric field poled bulk devices of neat and binary BAH chromophores exhibited significantly enhanced EO coefficients (r33) and poling efficiencies (r33/Ep) compared with state-of-the-art chromophores such as JRD1. The neat BAH13 devices with charge blocking layers produced very large poling efficiencies of 11.6 ± 0.7 nm2 V-2 and maximum r33 value of 1100 ± 100 pm V-1 at 1310 nm on hafnium dioxide (HfO2). These results were comparable to that of our recently reported BAY1 but with much lower loss (extinction coefficient, k), and greatly exceeding that of other previously reported OEO compounds. 3 : 1 BAH-FD : BAH13 blends showed a poling efficiency of 6.7 ± 0.3 nm2 V-2 and an even greater reduction in k. 1 : 1 BAH-BB : BAH13 showed a higher poling efficiency of 8.4 ± 0.3 nm2 V-2, which is approximately a 2.5-fold enhancement in poling efficiency vs. JRD1. Neat BAH13 was evaluated in plasmonic-organic hybrid (POH) Mach-Zehnder modulators with a phase shifter length of 10 μm and slot widths of 80 and 105 nm. In-device BAH13 achieved a maximum r33 of 208 pm V-1 at 1550 nm, which is ∼1.7 times higher than JRD1 under equivalent conditions.