Abstract
Wavelength conversion using cross‐gain modulation (XGM) in linear tapered‐waveguide semiconductor laser amplifiers (SLAs) has been investigated theoretically and compared with the nontapered semiconductor laser amplifier. For example, we have found that for the linear tapered‐waveguide SLA with a 450‐μm cavity length, a higher signal power is required to achieve an extinction ratio similar to that obtained by the conventional SLA with the same cavity length. However, a similar extinction ratio is observed for both conventional and linear tapered‐waveguide with the cavity length of 1200 μm. The difference between the extinction ratios for up and down conversions is less severe in a linear tapered‐waveguide SLA as compared to that for a conventional SLA. The rise time for the linear tapered‐waveguide is observed to be higher than that for the conventional SLA. It is possible to attain extinction‐ratio conservation using XGM for both up and down conversions in an SLA with a very long cavity length of 2400 μm. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 134–142, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20748