Optical modulators are vital for many applications, including telecommunication, data communication, optical computing, and microwave photonic links. A compact modulator with low voltage drive requirement, low power, high speed, and compatibility with CMOS foundry process is highly desirable. Current modulator technologies in Si suffer from trade-offs that constrain their power, performance (speed, drive voltage), and area. The introduction of additional materials to the silicon platform for efficient phase shift promises alternatives to relax those trade-offs. Si-organic-hybrid (SOH) devices demonstrate large modulation bandwidth leveraging the electro-optic (EO) effect and smaller drive voltage or footprint owing to a strong EO coefficient. In this study, we review various SOH modulators and describe their path towards integration to silicon, including their challenges associated with aging and temperature. We also briefly discuss other high-performance modulators such as plasmonic-organic-hybrid (POH), photonic-crystal-assisted SOH, and LiNbO3.

A detailed rate-equation-based model is developed to study carrier transport effects on optical and electrical characteristics of the Multiple Quantum Well Heterojunction Bipolar Transistor Laser in time-domain. Simulation results extracted using numerical techniques in small-signal regime predict significant enhancement in device optical bandwidth when multiple quantum wells are used. Cavity length and base width are also modified to optimize the optoelectronic performances of the device. An optical bandwidth of ≈60GHz is achieved in the case of 5 quantum wells each of 70Å widths and a cavity length of 200m.The observation of stimulated light emission (λ≈900nm) from the quantum well (QW) base region of the highspeed heterojunction bipolar transistor laser 1 (HBTL) has received significant attention in recent years. With a highly doped p-type base region, the transistor laser (TL) is expected to have a short radiative recombination lifetime that would make it faster than conventional optical sources for communication networks, i.e. diode lasers (DL).Thanks to its double functionality, i.e. electrical switching of the HBT and lasing operation, the TL has significant potential for ultrafast optoelectronic integrated circuits. As it is anticipated that the 3-terminal optoelectronic device will have a better optical bandwidth compared with a DL, optimization of QW-base structure is desirable. 2 Experimentally the optimization of the TL structure without taking into account the HBT response would be tedious, whereas only a few theoretical models have been developed for single quantum well (SQW) HBTL, for which simplified forms of conventional rate equations for DL have been implemented. 3,4,5 Recently a large signal analysis has been proposed 6 that simulates optical and electrical performances of a buried heterostucture TL with different number of QWs. However, this approach suffers from several drawbacks such as linear optical gain, which is only a good approximation for small signal analysis, and the neglect of tunneling effects between different QWs. In their work, the authors reported a recombination lifetime in the TL active region of

The Authors report an analytical model to investigate optoelectronic characteristics reliance of a Transistor Laser on Quantum Well Location. Using simulated base recombination lifetime, optical frequency response for different quantum-well locations extracted. Slipping the well towards the collector, improves the optical bandwidth where a maximum of ≈54 GHz is observed. No resonance peak, limiting factor in diode lasers, is occurred in this enhancement method. Analyzing current gain (β) as a function of the quantum well location, exhibits a decrease in β when the well moved in the direction of the collector so that a trade-off between optical and electrical properties of transistor laser is evident. The trade-off is utilized in conjunction with previously reported experimental researches to find an optimum place of quantum well for desired performance.

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