Optical feedback on linearity performance of 1.3- mu m DFB and multimode lasers under microwave intensity modulation

Under large signal modulation and quantitatively controlled optical feedback (from about -50 dB to -25 dB, from the end of approximately 2-m pigtails), the linearity performance of both a 1.3- mu m distributed-feedback (DFB) and a multimode laser is examined. Under proper bias levels and modulation frequencies, both lasers exhibit good linearity even with strong optical feedback. The DFB laser exhibits good linearity because of its coherence reduction, resulting from modulation-induced frequency chirping.<
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