Simulations of a sub-kilohertz linewidth laser in monolithic indium phosphide

Narrow-linewidth lasers play a crucial role in various applications, including sensing, coherent communication, and quantum communication. Semiconductor lasers achieving narrow linewidths employ long external cavities to extend photon lifetime within the resonator. For monolithically integrated (active-passive) platforms the loss of the passive waveguides puts a limit on this approach, however. To our knowledge, the state-of-the-art linewidth for such monolithic lasers stands at 10 kHz

Design optimization for energy-efficient pulse-switching networks in carrier-injection based Si-photonics

We compare pulse-switching operations in MZI- and ring-switches both experimentally and based on large-signal circuit simulations. With a modification in switch design and with optimization of phase modulator lengths, we show high-speed switches with potential for an over 3 dB improvement in energy consumption

Out-of-plane focussing polarization control grating couplers for photonic-spintronic integration

We demonstrate the first out-of-plane 2D focusing grating coupler (FGC), designed for compact photonic-spintronic integration allowing full polarization control of the emitted light. The couplers are designed for a standard 220nm-SOI platform and fabricated with 193 nm UV lithography. These couplers can find applicability as polarization (de)multiplexers, optical layer couplers or to realize optically enabled spintronic memory based on helicity dependent all-optical switching (AOS)[1,2]

Compact widely tunable laser integrated on an indium phosphide membrane platform

We present the design, fabrication, and characterization results of a compact, widely tunable laser realized on an indium phosphide membrane-on-silicon (IMOS) platform. The laser features a compact Mach–Zehnder interferometric structure as the wavelength-selective intracavity filter with a footprint of 0.13 mm2. The filter design is optimized to ensure narrow filter transmission and high side-mode-to-main-mode-ratio, enabling single-mode operation for the laser. The high optical confinement on the IMOS platform can support tight waveguide bends. Leveraging this, the laser achieves a short cavity length, further enhancing the single-mode operation. Measurement results indicate a threshold current of 29 mA and a maximum on-chip output power of approximately 3.6 dBm and wall plug efficiency of 1.8%. The side-mode suppression ratio ranges from 30 to 44 dB, with a tuning range spanning 40 nm, from 1555 to 1595 nm. A complete tuning lookup table is generated via an automated setup incorporating a stochastic search algorithm

Towards high-speed energy-efficient pulse-switching networks implemented in carrier-injection-based si-photonics

We show that carrier injection based Si-photonics modulators [1] can form the basis for building compact, low-loss and power efficient reconfigurable networks, enabling the switching of ps-pulse trains with sub-GHz repetition rates. The use of pre-emphasis-based activation [2] permits ns-scale switching transitions. Although the steady-state energy consumption in this platform is well studied, the impact of the dynamic energy consumption for these ns switching periods is not well known. Here, we show pre-emphasis-based sub-ns transitions and present a novel large-signal analysis that allows the driving scheme optimization for energy-efficient pulse switching

Analysis of hybrid mode-locking of two-section quantum dot lasers operating at 1.5 micron

For the first time a detailed study of hybrid mode-locking in two- section InAs/InP quantum dot Fabry-Pérot-type lasers is presented. The output pulses have a typical upchirp of approximately 8 ps/nm, leading to very elongated pulses. The mechanism leading to this typical pulse shape and the phase noise is investigated by detailed radio-frequency and optical spectral studies as well as time-domain studies. The pulse shaping mechanism in these lasers is found to be fundamentally different than the mechanism observed in conventional mode-locked laser diodes, based on quantum well gain or bulk material. ©2009 Optical Society of America

Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D) imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC) technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by high-bandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs

High-Power Continuously Tunable Terahertz Beat Note Generation Based on a Generic Photonic Integration Platform

We generate a continuously tunable terahertz beat note, with a maximum output power of 50 mW and frequency range from 807 to 915 GHz, by using the device implemented on a generic photonic integration platform

Simulations of a sub-kilohertz linewidth laser in monolithic indium phosphide

Narrow-linewidth lasers play a crucial role in various applications, including sensing, coherent communication, and quantum communication. Semiconductor lasers achieving narrow linewidths employ long external cavities to extend photon lifetime within the resonator. For monolithically integrated (active-passive) platforms the loss of the passive waveguides puts a limit on this approach, however. To our knowledge, the state-of-the-art linewidth for such monolithic lasers stands at 10 kHz