Laguerre fields strength and beam waist-dependent superluminal propagation of light pulse in atomic medium

We address the superluminal propagation of light in a four-level atomic medium. The superluminal propagation of the probe field is controlled and modified by the strength and waists of control driving fields. Around the origin of Laguerre coordinates in the x , y plane, localized depth of absorption and localized peaks of dispersion are noticed. The localized depth of absorption and dispersion can be narrowed and broadened by changing the beam waist. Increasing the beam waist, we observed broadening in the width of localized absorption and dispersion. Negative group index from - 10 to - 20 and negative group velocity from - 0.06 to - 0.12 c are observed at the low beam waist. At high beam waist, group index and group velocity remain the same which shows superluminal behaviour in this region. The modified results show potential applications in gravitational wave detection, soliton radar system and speeding up computer processing.