Phase Modulation of Photonic Band Gap Signal.

Zhiguo Wang,Mengqin Gao,Abdul Rasheed Mahesar,Yanpeng Zhang

doi:10.1038/srep28185

Abstract

We first investigate the probe transmission signal (PTS) and the four wave mixing band gap signal (FWM BGS) modulated simultaneously by the relative phase and the nonlinear phase shift in the photonic band gap (PBG) structure. The switch between the absorption enhancement of PTS and the transmission enhancement of PTS with the help of changing the relative phase and the nonlinear phase shift is obtained in inverted Y-type four level atomic system experimentally and theoretically. The corresponding switch in PTS can be used to realize all optical switches. On other hand, the relative phase and the nonlinear phase shift also play the vital role to modulate the intensity of FWM BGS reflected from the PBG structure. And it can be potentially used to realize the optical amplifier.

Highlights

We first investigate the probe transmission signal (PTS) and the four wave mixing band gap signal (FWM BGS) modulated simultaneously by the relative phase and the nonlinear phase shift in the photonic band gap (PBG) structure
According to the two groups of results, when remaining the nonlinear phase shift ∆ΦNunchanged, PTS can be switched from the transmission enhancement to the absorption enhancement gradually along with the relative phase ∆Φ
The PTS and the FWM BGS manipulated by the relative phase and the nonlinear phase shift in PBG structure are researched experimentally and theoretically

Summary

Result

In Fig. 3(a2), pression changes with the FWM BGSs are suppressed at the location of ∆2 = −∆1 and relative phase ∆Φ varying according to the dressing term G the intensity of the 2 2 ei∆Φ+i∆ΦN/d20 in supρ1(03) During this process, the strongest intensity of suppression of FWM BGS appears at ∆Φ = 0 (curve (iv)). When we change the detuning Δ1 from 0 MHz (Fig. 3(a1)) to 400 MHz (Fig. 3(b1)), corresponding to the nonlinear phase shift ∆ΦN changing from π/10 to 2/5π, the PTS can switch from the transmission enhancement of PTS to absorption enhancement of PTS because the dressing effect of E2 changes with the Figure 4. Compared Fig. 4(a2) with Fig. 4(a4), the intensity of suppression on FWM BGS at the same detuning is different when the relative phase is varying This is because the dressing effect of E2 is varying with ∆Φ changing. We can modulate PTS and FWM BGS through changing the relative phase ∆Φ and the nonlinear phase shift ∆ΦN

Discussion

Methods