Group delay tuning in active fiber Bragg gratings: From superluminal to subluminal pulse reflection

Group delay tuning of optical pulses in pumped asymmetric fiber Bragg gratings below lasing threshold is theoretically proposed. A gain-controlled transition from superluminal to subluminal pulse reflection is analytically investigated in uniform gratings with a ð phase shift and in tapered gratings.PACS: 42.25.Bs, 42.70.Qs, 03.65.XpGroup delay tuning of optical pulses in pumped asymmetric fiber Bragg gratings below lasing threshold is theoretically proposed. A gain-controlled transition from superluminal to subluminal pulse reflection is analytically investigated in uniform gratings with a ð phase shift and in tapered gratings. PACS: 42.25.Bs, 42.70.Qs, 03.65.Xp