System Demonstration of a 40 Gb/s Time and Wavelength-Set Division Multiplexing PON

Your 350-character (incl. spaces) abstract, which will appear in the conference program, should be an explicit summary of the paper that states the problem, the methods used, and the major results and conclusions. It should be complementary to rather than a repeat of the title. Introduction Time and wavelength division multiplexing passive optical network (TWDM-PON) was selected as the prime solution for the second next generation PON (NG-PON2) [ref draft G.989 ?]. An important challenge is to realize a tunable transceiver in the optical network unit (ONU) at a low cost. Solutions for tunable receivers in the downstream direction were presented e.g. in [Murano]. The present paper focuses on a cheap solution for the tuning upstream transmitter based on a new time and wavelength set-division multiplexing (TWSDM) approach that avoids the cost of a thermoelectric cooler (TEC) in a thermally tuned distributed feedback (DFB) laser (cf. [Wolfgang ECOC 2011, 2012]). Instead of heating and cooling down the laser to reach a desired wavelength channel, the approach exploits the cyclic property of an arrayed waveguide grating and allows for just heating up the laser to the next pass band of the same wavelength-set. The present paper reports the first system demonstration of the TWSDM concept with automated wavelength control. Two important technical challenges needed to be addressed to achieve this goal: 1. The response time of the wavelength control had to be optimized within the boundaries of the different thermal time constants for heat transfer between heating resistor and laser and between laser and temperature sensor.