A general formula is given that expresses frequency chirping in some types of external intensity modulators, such as the loss modulator, directional-coupler-type modulator, Mach-Zehnder interferometry-type modulator, and total-internal-reflection-type modulator. The chirping phenomenon treated is caused by the phase modulation due to an accompanied refractive index change. It is uniquely expressed in terms of an alpha -parameter that contributes to frequency chirping in the same manner as in the direct modulation of a semiconductor laser. In addition, the transmission bandwidth of a single-mode fiber system using an external modulator is discussed and compared with the results obtained utilizing direct laser modulation. >

Frequency chirping in external modulators

Semiconductor photonic integrated circuits (PICs) refer to that subset of optoelectronic integrated circuits (OEICs) which focus primarily on the monolithic integration of optically interconnected guided-wave optoelectronic devices. The principal motivation for PIC research is the expected cost reduction and packaging robustness associated with replacing individually aligned, single-mode optical connections between discrete optoelectronic devices with lithographically produced integrated waveguides. This field has recently seen significant advances resulting from improved III-V epitaxial crystal growth and related processing techniques. A discussion is presented of the design and fabrication issues, illustrated by a number of recently demonstrated InP-based PICs. >

Semiconductor photonic integrated circuits

A description is given of a GaAs-AlGaAs, loaded-line traveling-wave modulator which has achieved bandwidths up to 36 GHz to date with low ( >

High-speed III-V semiconductor intensity modulators

Integrated OpticsIntegrated Optics and Optical SwitchingIntegrated Optics: Theory and TechnologyIntroduction to Integrated OpticsElements of Photonics, Volume IIEncyclopedic Handbook of Integrated OpticsOptical Fiber Communication Conference and Sixth International Conference on Integrated Optics and Optical Fiber CommunicationIntegrated Optical Circuits and ComponentsIntegrated OpticsAdvances in Integrated OpticsFundamentals of Fibre Optics in Telecommunication and Sensor SystemsIntegrated OpticsIntegrated Optics, Microstructures, and SensorsMulti-Photon Quantum Information Science and Technology in Integrated OpticsIntegrated Optics, Microstructures, and SensorsIntegrated PhotonicsOptics and LasersA Consideration of Possibilities and Difficulties in Passive Circuits in Integrated OpticsSemiconductor Integrated Optics for Switching LightIntegrated OpticsIntegrated OpticsAdvanced Materials for Integrated Optical WaveguidesIntroduction to Semiconductor Integrated OpticsCommercial Integrated OpticsIntegrated OpticsIntegrated Optics and MicrostructuresElectromagnetic Principles of Integrated OpticsIntegrated Optics and Micro-Optics with PolymersIntroduction to Integrated OpticsIntegrated Optics SuppliersIntegrated Optics: Theory and TechnologyDiffractive Optics and Optical MicrosystemsIntegrated Optics and OptoelectronicsFiber and Integrated OpticsEncyclopedic Handbook of Integrated OpticsFirst International Conference on Integrated Optical Circuit EngineeringIntegrated OpticsIon Exchange in Single Crystals for Integrated Optics and OptoelectronicsOptics and LasersIntegrated Optics: Devices, Materials, and Technologies

http://ieeexplore.ieee.org/iel5/3/23092/01072971.pdf

Integrated optics

The application market for Photonic Integrated Circuits (PICs) is rapidly growing. Photonic integration is the dominant technology in high bandwidth communications and is set to become dominant in many fields of photonics, just like microelectronics in the field of electronics. PICs offer compelling performance advances in terms of precision, bandwidth, and energy efficiency. To enable uptake in new sectors, the availability of highly standardized (generic) photonic integration platform technologies is of key importance as this separates design from technology, reducing barriers for new entrants. The major platform technologies today are Indium Phosphide (InP)-based monolithic integration and Silicon Photonics. In this perspective paper, we will describe the current status and future developments of InP-based generic integration platforms.

Past, present, and future of InP-based photonic integration

Monolithic integration of a 1.55-μm InGaAsP/InP distributed feedback (DFB) laser and an electroabsorption (EA) modulator was studied. The difference between the lasing photon energy and the bandgap energy of the modulator waveguide was designed to be 30-40 meV, taking into account the linewidth-enhancement factor and the zero-bias absorption loss. The integrated devices were grown by three-step vapor phase epitaxy (VPE). The CW threshold current at 20°C of the DFB laser part with a buried heterostructure was 30-60 mA and the breakdown voltage of the modulator part with a strip-loaded stripe geometry was 20-40 V, and these values indicated satisfactory crystal quality in the VPE epitaxial layers. The operating voltage of the modulator to give on:off ratios of 10:1 and 100:1 was 1.5- 4 V and 2.5-6.5 V, respectively, depending on the length in the range 200-500 \mu m. A 3-dB bandwidth of about 2.5 GHz and a linewidth-enhancement factor of about 1.6 were obtained for the integrated modulator.

H. Tanaka

Papers

Monolithic integration of InGaAsP/InP distributed feedback laser and electroabsorption modulator by vapor phase epitaxy