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Mark Cappuzzo

Publications and source records attributed to Mark Cappuzzo.

9 recordsLinked to original sources
arXiv2026

Unveiling charge dynamics on the generation of high extinction wide pulse generation on thin-film lithium tantalate

We experimentally demonstrate high-extinction optical pulse generation in thin-film lithium tantalate (TFLT), achieving a wide range of pulse widths with sharp rise and fall edges, without measurable distortion or long temporal tails. We further provide a direct one-to-one comparison with thin-film lithium niobate (TFLN) modulators under identical measurement conditions. Our results reveal that the distorted pulse response observed in TFLN originates from charge activation and transport, whereas the distortion-free response in TFLT is enabled by the substantially larger activation energy of defect-related charge carriers. This larger activation barrier suppresses leakage-current-induced charging dynamics, thereby enabling stable and distortion-free pulse generation. The successful generation of high-extinction, distortion-free optical pulses in TFLT can play a significant role in integrated quantum photonic technologies, particularly for qubit preparation, measurement, and fast feedback circuits.

physics.optics↗
arXiv2026

Stable thin-film lithium tantalate modulators operating at high temperature for uncooled operation

We demonstrate stable operation of a thin-film lithium tantalate (TFLT) modulator at very high operating temperatures. We show that the electro-optic modulation and bandwidth of the TFLT modulators are not affected by high-temperature operation, and both waveguide and resonant modulators are DC-bias stable even at 120{\deg}C. At higher temperatures, we even observe 10% reduction of the V{\pi} of the modulator. Our results position TFLT modulators as a strong candidate for uncooled operation in co-packaged optics.

physics.optics↗
arXiv2026

High-power handling and bias stability of thin-film Lithium Tantalate microring and coupling resonators

In this paper, we demonstrate the ultra-high-power handling capability and DC bias stability of optical microring and electro-optic (EO) coupling resonators on the thin-film lithium tantalate (TFLT) platform. We show that, with annealing, oxide-cladded TFLT resonators can handle several watts (4W) of circulating power with minimal frequency shift and no observable photo-refractive effect. Furthermore, we demonstrate a compact 2mm coupling modulator achieving a low Vpi of 3V with stable bias and phase control in the telecom C-band.

physics.optics↗
arXiv2025

A tunable FP Perot coupling interferometer on thin-film lithium niobate

We experimentally show an electro-optic tunable Fabry-Perot cavity on thin-film lithium niobate (TFLN). Instead of tuning the cavity phase and thus resonant frequency, we demonstrate modulation of the FP cavity by tuning the cavity mirrors via the electro-optic effect in the couplers. We enable full tuning of a low-Q FP cavity with only 3.5 V Vpi and a very short 3.5 mm long Mach-Zehnder interferometer (MZI) mirror.

physics.optics↗
arXiv2023

A surface-normal photodetector as nonlinear activation function in diffractive optical neural networks

Optical neural networks (ONNs) enable high speed parallel and energy efficient processing compared to conventional digital electronic counterparts. However, realizing large scale systems is an open problem. Among various integrated and non-integrated ONNs, free-space diffractive ONNs benefit from a large number of pixels of spatial light modulators to realize millions of neurons. However, a significant fraction of computation time and energy is consumed by the nonlinear activation function that is typically implemented using a camera sensor. Here, we propose a novel surface-normal photodetector (SNPD) with a nonlinear response to replace the camera sensor that enables about three orders of magnitude faster (5.7 us response time) and more energy efficient (less than 10 nW/pixel) response. Direct efficient vertical optical coupling, polarization insensitivity, inherent nonlinearity with no control electronics, low optical power requirements, and the possibility of implementing large scale arrays make the SNPD a promising nonlinear activation function for diffractive ONNs. To show the applicability, successful classification simulation of MNIST and Fashion MNIST datasets using the measured response of SNPD with accuracy comparable to that of an ideal ReLU function are demonstrated.

physics.optics↗