Broad-band light source using mutually injected Fabry-Pe/spl acute/rot laser diodes for WDM-PON

We propose and demonstrate a new broad-band light source (BLS) for a wavelength division multiplexing-passive optical network (WDM-PON) based on the wavelength locked Fabry-Pe/spl acute/rot laser diodes (F-P LDs). By mutual injection between two antireflection-coated F-P LDs, we realized a broad-band light with a low relative intensity noise. By using the proposed BLS for wavelength locking of the F-P LD, we achieve color-free operation of the optical network termination with Manchester coded data. We also demonstrate a WDM-PON based on the proposed BLS.

I. Introduction

The passive optical network (PON) based on wavelength division multiplexing (WDM) has been investigated extensively for the fiber-to-the-home (FTTH), since it provides almost unlimited bandwidth to the subscribers with protocol and bit rate transparencies. However, implementation of WDM-PON requires a cost-effective WDM source. Recently, the wavelength locked Fabry–Pérot laser diode (F–P LD) with an external spectrum-sliced broad-band light injection was proposed [1]. It is a very effective solution to reduce the installation and management costs, since the optical network termination (ONT) can be operated wavelength independently, i.e., color-free operation [2]. To implement WDM-PON based on the wavelength locked F–P LD, a low-cost broad-band light source (BLS) is essential. The BLS can be realized with a light-emitting diode (LED), a superluminescent diode (SLD), or an amplified spontaneous emission (ASE) based on erbium-doped fiber amplifier (EDFA) [3], [4]. Fig. 1. Experimental setup for WDM-PON with proposed BLS. The LED does not provide enough output power and the others are still expensive solutions even though they can provide much higher output power than the LED.