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Paradigm Shift of On-Chip Interconnects from Electrical to Optical
Published in Thomas Noulis, Noise Coupling in System-on-Chip, 2018
Swati Joshi, Amit Kumar, Brajesh Kumar Kaushik
Modulators are essential components in photonics circuits. They control the characteristics of light through the circuits according to an external modulating signal. There are stringent requirements for optical modulators to meet complex future demands, such as high speed, low energy per bit, compact design, low loss, large optical bandwidth, modulation depth, low-temperature sensitivity, CMOS compatible process flow, and low drive voltage. The thermo-optic effect, electro-optic effect, and microelectromechanical systems (MEMS) are some of the current optical modulation schemes. In an electro-optic modulator, the electro-optic effect is used to modulate a beam of light. The modulation can be in terms of change of intensity, phase, or polarization of the output beam. MEMS and thermal effects find less application in current devices due to their slow speed. An optical modulation scheme is shown in Figure 14.27.
Optical Control Elements
Published in Chunlei Guo, Subhash Chandra Singh, Handbook of Laser Technology and Applications, 2021
Electro-optic modulators using the Kerr effect or the Pockels effect are available, although most modern electro-optic modulators are based on Pockels cells. These modulators exploit the voltage-dependent birefringence induced in some crystalline materials when they are subjected to an external electric field. The Pockels effect has a linear relationship and the electro-optic Kerr effect a quadratic relationship between the indicatrix of the material and the applied electric field. Birefringence is a difference in refractive index dependent on the alignment of the electric field vector with crystal lattice directions.
Temporal Lens and Adaptive Electronic/Photonic Equalization
Published in Le Nguyen Binh, Advanced Digital, 2017
Electro-optic modulator is an optical device that is used to manipulating either the phase and/or amplitude of the light beam via the change of the refractive index of the medium by applying an electric field, the electro-optic effect. In this section, only phase modulation of the modulated beam is discussed. The electro-optic phase modulator lens has been used very popularly in pulse compression for ultra-short optical pulses, such as a few pico-seconds or a few hundred femto-seconds.
Progress in wafer bonding technology towards MEMS, high-power electronics, optoelectronics, and optofluidics
Published in International Journal of Optomechatronics, 2020
Jikai Xu, Yu Du, Yanhong Tian, Chenxi Wang
Electro-optic modulators are essential building blocks for modern telecommunication networks, quantum photonics, and microwave-photonic systems. However, current LiNbO3-based modulators are suffered from bulky, expensive, low bandwidth, and need high operating voltages. Cheng Wang et al. from Marko Loncar’s group demonstrate monolithically integrated thin-film LiNbO3-based modulators that can overcome these trade-offs.[102] They propose a 50:50 Y-junction Mach-Zehnder interferometer, which allows the input light to split into two LN waveguides. The device configuration is presented in Figure 5(d). The electric field has opposite influences on the two LN waveguides, making an optical phase delay in one arm while a phase advance in the other one. This phase difference can lead to constructive/destructive interference at the output of Y-junction, resulting in amplitude modulation. According to the experimental results, the modulator has a high bandwidth even working at a CMOS-compatible voltage, as shown in Figure 5(e). The data transmission rates can reach 210 Gbit s−1 and achieve an ultralow optical loss of 0.5 decibels. Therefore, this approach has a potential application in photonic quantum computation.
Optical response properties of a hybrid electro-optomechanical system interacting with a qubit
Published in Journal of Modern Optics, 2022
Tarun Kumar, Surabhi Yadav, Aranya B. Bhattacherjee
Electro-optic modulators (EOMs) used in optical communication systems have the ability to modulate an optical field using an electric field. One of the major challenge to implement such an EOM is low power consumption [78]. EOMs based on Pockels effect and Kerr effect require large components together with high driving voltage [79,80], leading to high energy dissipation [81]. EOMs based on the electro-absorption effects are also not fully successful due to the weakness of the electro-optic absorption effect [82]. These limitations led to a novel proposal of a hybrid EOM system composed of a three-level medium confined inside a tunable cavity coupled to an electro-mechanical system [83].