Frequency tuning characteristics and WDM channel access of the semiconductor three-branch Y3-lasers

SPEED DMON:Cache Coherence on an Optical Multichannel Interconnect Architecture

“…The fan-in/fan-out limitations of the star-coupler due to optical power budget [20] can limit scalability of broadcast and home channels to a few hundred nodes [15]. The fiber fan-in of arrayed light sources or the tunability of a tunable source can also limit scalability of home channels to approximately a hundred nodes [16]. However, these limitations may be overcome by the following.…”

Design of widely tunable semiconductor three-branch lasers

“…This would be the case if the tuning segments are made of passive waveguides or are tuned electrooptically. In an all active laser structure, such as in [17], [18], current changes also induce gain and loss changes in the laser segments, gain spectrum of the medium can shift, current heating can induce index changes and cross-talk between different segments, spurious reflections can affect the filter shape and its tuning, etc. These additional effects can be accounted in a more refined model of the laser.…”

“…While an integrated waveguide 1 x N splitter can be built [25], it is physically large and is lossy for small N (e.g.. N < 5). For small N it is more efficient to make multibranch lasers by using several Y-branches in cascade [ 171, [18]; for example an N-branch laser can be made using a cascade of (N -1) Y-junctions. The interaction between these three cavity lengths can be characterized by only two length differences.…”

“…Several new approaches have been proposed and demonstrated recently that produce semiconductor lasers with 20-100 nm tuning ranges [4]- [19]. Among these is the three-branch Y3-laser [17], [18], which demonstrated a tuning range of 45 nm (5.6 THz), access to 50 frequency channels with a two-current control, and potential access to more than 100 channels. In this paper we describe the design principles of such widely tunable Y3-Manuscript received March 15, 1993; revised September 1, 1994.…”

“…In these discretely tunable structures, the laser tunes with the filter by jumping from mode to mode. Such laser structures include the grating-assisted coupler laser [4], [5], the DBR laser with two slightly-different grating superstructures [6]-[ 111, the Y-branch [ 121, [ 131 and the asymmetric Y-branch (AYB) laser [13]- [16], and the three-branch Y3-laser [17], [18]. A widely tunable laser which combines the gratingassisted coupler and a superstructure grating has also been demonstrated [19].…”