Densely integrated microring resonator based photonic devices for use in access networks

Two reconfigurable optical add-drop multiplexers, operating in the second or third telecom window, as well as a 1x4x4 reconfigurable λ-router operating in the second telecom window, are demonstrated. The devices have a footprint less than 2 mm2 and are based on thermally tunable vertically coupled microring resonators fabricated in Si3N4/SiO2

Photonic RF signal processors

The purpose of this thesis is to explore the emerging possibilities of processing radiofrequency (RF) or microwave signals in optical domain, which will be a key technology to implement next-generation mobile communication systems and future optical networks. Research activities include design and modelling of novel photonic architectures for processing and filtering of RF, microwave and millimeter wave signals of the above mentioned applications. Investigations especially focus on two basic functions and critical requirements in advanced RF systems, namely: • Interference mitigation and high Q tunable filters. • Arbitrary filter transfer function generation. The thesis begins with a review on several state-of-the-art architectures of in-fiber RF signal processing and related key optical technologies. The unique capabilities offered by in-fiber RF signal processors for processing ultra wide-band, high-frequency signals directly in optical domain make them attractive options for applications in optical networks and wide-band microwave signal processing. However, the principal drawbacks which have been demonstrated so far in the in-fiber RF signal processors arc their inflexible or expensive schemes to set tap weights and time delay. Laser coherence effects also limit sampling frequency and introduce additional phase-induced intensity noise

Adaptive applications of OPTO-VLSI processors in WDM networks

Communication is an inseparable part of human life and its nature continues to evolve and improve. The advent of laser was a herald to the new possibilities in the communication world. In recent years technologies such as Wavelength Division Multiplexing (WDM) and Erbium Doped Fiber Amplifiers (EDFA) have afforded significant boost to the practice of optical communication. At the heart of this brave new world is the need to dynamically/ adaptively steer/route beams of light carrying very large amounts of data. In recent years many techniques have been proposed for this purpose by various researchers. In this study we have elected to utilise the beam-steering capabilities of Opto-VLSI processors to investigate band-pass filtering and channel equalisation as two possible and practical applications in WDM networks

Dispositivos fotónicos con base sol-gel y de silicio

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Óptica, leída el 01/07/2013Depto. de ÓpticaFac. de Ciencias FísicasTRUEunpu

Opto-VLSI based WDM multifunction device

The tremendous expansion of telecommunication services in the past decade, in part due to the growth of the Internet, has made the development of high-bandwidth optical net-works a focus of research interest. The implementation of Dense-Wavelength Division Multiplexing (DWDM) optical fiber transmission systems has the potential to meet this demand. However, crucial components of DWDM networks – add/drop multiplexers, filters, gain equalizers as well as interconnects between optical channels – are currently not implemented as dynamically reconfigurable devices. Electronic cross-connects, the traditional solution to the reconfigurable optical networks, are increasingly not feasible due to the rapidly increasing bandwidth of the optical channels. Thus, optically transparent, dynamically reconfigurable DWDM components are important for alleviating the bottleneck in telecommunication systems of the future. In this study, we develop a promising class of Opto-VLSI based devices, including a dynamic multi-function WDM processor, combining the functions of optical filter, channel equalizer and add-drop multiplexer, as well as a reconfigurable optical power splitter. We review the technological options for all optical WDM components and compare their advantages and disadvantages. We develop a model for designing Opto-VLSI based WDM devices, and demonstrate experimentally the Opto-VLSI multi-function WDM device. Finally, we discuss the feasibility of Opto-VLSI WDM components in meeting the stringent requirements of the optical communications industry

Opto-VLSI processing for reconfigurable optical devices

The implementation of Wavelength Division Multiplexing system (WDM) optical fibre transmission systems has the potential to realise this high capacity data rate exceeding 10 Tb/s. The ability to reconfigure optical networks is a desirable attribute for future metro applications where light paths can be set up or taken down dynamically as required in the network. The use of microelectronics in conjunction with photonics enables intelligence to be added to the high-speed capability of photonics, thus realising reconfigurable optical devices which can revolutionise optical telecommunications and many more application areas. In this thesis, we investigate and demonstrate the capability of Opto-VLSI processors to realise a reconfigurable WDM optical device of many functions, namely, optical multiband filtering, optical notch filtering, and reconfigurable-Optical-Add-Drop Multiplexing (ROADM). We review the potential technologies available for tunable WDM components, and discuss their advantages and disadvantages. We also develop a simple yet effective algorithm that optimises the performance of Opto-VLSI processors, and demonstrate experimentally the multi-function WDM devices employing Opto-VLSI processors. Finally, the feasibility of Opto-VLSI-based WDM devices in meeting the stringent requirements of the optical communications industry is discussed

Nonlinear photonics with applications in lightwave communications

This doctoral dissertation investigates the use of nonlinear photonics in targeted Lightwave communication applications. Different highly nonlinear optical materials have been considered for the investigation of Lightwave communications data carriers, with a focus on the optical carrier pulsewidth. A state-of-the-art novel method has been developed to measure pico-second optical carrier pulses using highly nonlinear optical fiber. This method is based on the nonlinear optical loop mirror (NOLM), with consideration focused on the third order nonlinearity. Silicon is considered to be one of the most attractive materials for photonics integrated circuit technology (PIC) due to its compatibility with complementary metal oxide semiconductor (CMOS). As such, the method has been applied to the SOI platform Mach-Zehnder interferometer (MZI), also by considering the third order nonlinearity. In the NOLM approach, the picosecond optical data carrier pulsewidth is measured by using an optical power meter. Simulations for both the self-phase and cross-phase modulation schemes are carried out, and as expected, the cross phase modulation gives an increment in the sensitivity twice that of the self-phase modulation. Due to very high repetition rates of the order 10 GHz, the effect of counter propagating non-linear interactions in the NOLM are also considered in the theoretical evaluation. In the experimental validation, the pulses from an active fiber mode-locked laser at a repetition rate of 10 GHz were incrementally temporally dispersed using an SMF-28 fiber. The optical data carrier pulses over a range of 2-10 ps were successfully measured with a resolution of 0.25 ps. By extrapolating the theoretical evaluation and by selecting different physical parameters for the setup, the method was found to exhibit an extended range of 0.25 to 40 ps.;The concept described above is then extended to the investigation of nonlinear SOI devices using an MZI, thus miniaturizing the setup. In this investigation, the silicon waveguide has been simulated for self-phase and cross-phase modulation by solving the nonlinear Schrodinger equations using the split step method. Silicon has strong two photon absorption at telecommunication wavelengths, i.e. 1550 nm, and therefore all nonlinear losses (i.e. TPA and free carriers generated through TPA) are included in the split step simulations. The results obtained show that the on-chip nonlinear MZI (based on the SOI platform) can also be used for the measurement of optical data carrier pulse-widths of up to 10 ps. In the last part of this doctoral dissertation, a novel design for a temperature insensitive MZI is presented. Temperature dependence is one of the main challenges in the design of the SOI platform due to the large thermo-optic coefficient of its core material. A change in temperature can cause the device properties to deviate significantly, and can also alter the nonlinear properties of the device. Therefore, a design of an all-passive athermal MZI device based on the SOI platform has been developed and investigated. The MZI's temperature compensation is achieved by optimizing the relative length of the wire and subwavelength grating arms, and by tailoring the thermal response of the subwavelength structure. The simulation results of the athermal MZI design indicated that an overall temperature sensitivity of 7.5 pm/K could be achieved over a 100 nm spectral range near the 1550 nm region.This doctoral dissertation investigates the use of nonlinear photonics in targeted Lightwave communication applications. Different highly nonlinear optical materials have been considered for the investigation of Lightwave communications data carriers, with a focus on the optical carrier pulsewidth. A state-of-the-art novel method has been developed to measure pico-second optical carrier pulses using highly nonlinear optical fiber. This method is based on the nonlinear optical loop mirror (NOLM), with consideration focused on the third order nonlinearity. Silicon is considered to be one of the most attractive materials for photonics integrated circuit technology (PIC) due to its compatibility with complementary metal oxide semiconductor (CMOS). As such, the method has been applied to the SOI platform Mach-Zehnder interferometer (MZI), also by considering the third order nonlinearity. In the NOLM approach, the picosecond optical data carrier pulsewidth is measured by using an optical power meter. Simulations for both the self-phase and cross-phase modulation schemes are carried out, and as expected, the cross phase modulation gives an increment in the sensitivity twice that of the self-phase modulation. Due to very high repetition rates of the order 10 GHz, the effect of counter propagating non-linear interactions in the NOLM are also considered in the theoretical evaluation. In the experimental validation, the pulses from an active fiber mode-locked laser at a repetition rate of 10 GHz were incrementally temporally dispersed using an SMF-28 fiber. The optical data carrier pulses over a range of 2-10 ps were successfully measured with a resolution of 0.25 ps. By extrapolating the theoretical evaluation and by selecting different physical parameters for the setup, the method was found to exhibit an extended range of 0.25 to 40 ps.;The concept described above is then extended to the investigation of nonlinear SOI devices using an MZI, thus miniaturizing the setup. In this investigation, the silicon waveguide has been simulated for self-phase and cross-phase modulation by solving the nonlinear Schrodinger equations using the split step method. Silicon has strong two photon absorption at telecommunication wavelengths, i.e. 1550 nm, and therefore all nonlinear losses (i.e. TPA and free carriers generated through TPA) are included in the split step simulations. The results obtained show that the on-chip nonlinear MZI (based on the SOI platform) can also be used for the measurement of optical data carrier pulse-widths of up to 10 ps. In the last part of this doctoral dissertation, a novel design for a temperature insensitive MZI is presented. Temperature dependence is one of the main challenges in the design of the SOI platform due to the large thermo-optic coefficient of its core material. A change in temperature can cause the device properties to deviate significantly, and can also alter the nonlinear properties of the device. Therefore, a design of an all-passive athermal MZI device based on the SOI platform has been developed and investigated. The MZI's temperature compensation is achieved by optimizing the relative length of the wire and subwavelength grating arms, and by tailoring the thermal response of the subwavelength structure. The simulation results of the athermal MZI design indicated that an overall temperature sensitivity of 7.5 pm/K could be achieved over a 100 nm spectral range near the 1550 nm region

An introduction to InP-based generic integration technology

Photonic integrated circuits (PICs) are considered as the way to make photonic systems or subsystems cheap and ubiquitous. PICs still are several orders of magnitude more expensive than their microelectronic counterparts, which has restricted their application to a few niche markets. Recently, a novel approach in photonic integration is emerging which will reduce the R&D and prototyping costs and the throughput time of PICs by more than an order of magnitude. It will bring the application of PICs that integrate complex and advanced photonic functionality on a single chip within reach for a large number of small and larger companies and initiate a breakthrough in the application of Photonic ICs. The paper explains the concept of generic photonic integration technology using the technology developed by the COBRA research institute of TU Eindhoven as an example, and it describes the current status and prospects of generic InP-based integration technology

An introduction to InP-based generic integration technology

Photonic integrated circuits (PICs) are considered as the way to make photonic systems or subsystems cheap and ubiquitous. PICs still are several orders of magnitude more expensive than their microelectronic counterparts, which has restricted their application to a few niche markets.Recently, a novel approach in photonic integration is emerging which will reduce the R&D and prototyping costs and the throughput time of PICs by more than an order of magnitude. It will bring the application of PICs that integrate complex and advanced photonic functionality on a single chip within reach for a large number of small and larger companies and initiate a breakthrough in the application of Photonic ICs. The paper explains the concept of generic photonic integration technology using the technology developed by the COBRA research institute of TU Eindhoven as an example, and it describes the current status and prospects of generic InP-based integration technology.Funding is acknowledged by the EU-projects ePIXnet, EuroPIC and PARADIGM and the Dutch projects NRC Photonics, MEMPHIS, IOP Photonic Devices and STW GTIP. Many others have contributed and the authors would like to thank other PARADIGM and EuroPIC partners for their help in discussions, particularly Michael Robertson (CIP).This is the final published version distributed under a Creative Commons Attribution License. It can also be viewed on the publisher's website at: http://iopscience.iop.org/0268-1242/29/8/08300