Abstract: A method and system is provided which enables an n channel system to be upgraded into at least an (n−1)+p channel system wherein p>1, and wherein the n−1 channels are substantially wider channels than the p channels. n uncooled inexpensive lasers not requiring optical isolators provide optical signals to the n broad channels, and p temperature compensated cooled lasers having optical isolators provide optical signals to the p channels. Advantageously, the system can be installed at a reasonable cost to the first n users and be upgraded in number of channels and cost as the need for the system to evolve and grow arises. Furthermore, the upgrade accomplished with disruption to only one user whereas the remaining n−1 are not disturbed and can continue to use the system during the upgrade. This obviates the problems associated with justifying the cost of providing p channels for only n subscribers, wherein the p channels require more expensive cooled lasers.

Abstract: A method and system is provided wherein an n channel system is equipped with n uncooled inexpensive lasers not requiring optical isolators provide optical signals to the n broad channels. Advantageously, the system can be installed at a reasonable cost to the first n users and be upgraded in number of channels and cost as the need for the system to evolve and grow arises. Each of the n uncooled lasers are tuned such that at ambient temperature, their central wavelength is below their respective channel mid wavelength.