In Europe a number of technology platforms for generic integration are being created for photonic integrated circuits (PICs); in Silicon, in passive dielectrics, and in Indium Phosphide. Such platforms are on the brink of commercialization, they offer a range of calibrated building blocks from which application specific PICs can be built and allow simplified, reduced cost access to a standardised technology, but presently only InP based platforms allow the integration of optical gain blocks; the essential feature of a semiconductor laser. The wavelength is constrained by the platform, usually C-band, but in the near future we expect other wavelengths in the 1.3μm-2.0μm range will be addressed. A frozen platform technology may not seem an ideal starting point for novel laser research but for what may be appear to be lost in epitaxial and process flexibility, much more is gained through a new-found ability to build up complex circuits quickly to deliver new and interesting laser based functionality. Building blocks such as reflectors (a distributed Bragg reflector (DBR) or a multimode interference reflector (MIR)), an amplifier section, and passive waveguides, can be built up by designers into integrated semiconductor lasers of a wide variety of types. This ready integration of novel sources with other circuit functionality can address a wide range of applications in telecoms, datacoms, and fibre based sensing systems. In this paper we describe a number of recent developments on generic InP-based platforms ranging from the fabrication of simple Fabry-Perot lasers, through tuneable DBR lasers, multi-wavelength comb lasers, picosecond pulse lasers and ring lasers.
A cost-effective solution to provide higher data rates in wireless communication system is to push carrier wave
frequencies into millimeter wave (MMW) range, where the frequency bands within the E-band and F-band have been
allocated. Photonics is a key technology to generate low phase noise signals, offering methods of generating continuous
MMW with varying performance in terms of frequency bandwidth, tunability, and stability.
Recently, we demonstrated for the first time of our knowledge the generation of a 95-GHz signal by optical heterodyning
of two modes from different channels of a monolithically integrated arrayed waveguide grating multi-wavelength laser
(AWGL). The device uses an arrayed waveguide grating (AWG) as an intra-cavity filter. With up to 16-channel sources
with independent amplifiers and a booster amplifier on the common waveguide, the laser cavity is formed between
cleaved facets of the chip. The two wavelengths required for optical heterodyning are generated activating
simultaneously two channel SOAs and the Boost amplifier.
In this work, we analyze the effect on the dual-wavelength operation of the Boost SOA, which is shared by two
wavelengths. Mapping the optical spectrum, sweeping the two channel and Boost bias currents, we show the interaction
among the different SOAs two find the regions of dual wavelength operation. The size of dual wavelength operation
region depends greatly on the Boost SOA bias level. Initial results of a numerical model of the AWGL will be also
presented, in which a digital filter is used to implement the AWG frequency behavior.
In this paper we investigate options for monolithically integrated multiwavelength transmitters in indium phosphidebased
materials. In particular, we focus on transmitters that use arrayed waveguide gratings as wavelength selective
elements. The multiwavelength lasers that simultaneously emit on different wavelength channels are crucial in Fiber-tothe-
Home systems because they increase the bandwidth and the transmission capacity of such optical networks.