All-optical flip-flop operation based on asymmetric active-multimode interferometer bi-stable laser diodes

H Jiang,K Tsuruda,T Hagio,K Hamamoto,J Xu,M Jizodo,S Matsuo,Y Chaen,C Peucheret

doi:10.1364/oe.19.00b119

Abstract

We demonstrate fast and low energy all optical flip-flop devices based on asymmetric active-multimode interferometer using high-mesa waveguide structure. The implemented devices showed high speed all-optical flip-flop operation with 25 ps long pulses. The rising and falling times of the output signal were 121 ps and 25 ps, respectively. The required set and reset pulse energies were only 7.1 fJ and 3.4 fJ, respectively.

Highlights

The amount of network data-traffic keeps increasing at an annual rate of 40% in Japan, to a large extent due to the increase in the amount of video information transmitted over the internet [1,2]
All-optical flip-flops offer one of the key functionalities for such all-optical routers since they can act as optical random access memory (RAM) elements
It can be seen that a low hysteresis threshold Ith of 60 mA, and a wide hysteresis window ∆Ihys% of 15% could be realized even in high-mesa waveguide structures

Summary

Introduction

The amount of network data-traffic keeps increasing at an annual rate of 40% in Japan, to a large extent due to the increase in the amount of video information transmitted over the internet [1,2]. The implemented devices showed a wide hysteresis window, together with superior single-wavelength emission (λ= 1556 nm, side-mode suppression ratio SMSR= 30 dB, without using grating structures) [14], and achieved all optical bi-stable switching operation [5]. As the active-MMI phenomenon requires coherence, high-mesa with asymmetric active-MMI results in single wavelength emission, namely “interference in the longitudinal mode” [18] Implemented devices of this type have shown single-wavelength emission with a SMSR of 30 dB [5]. The access waveguide width was set to be 3 μm The high-mesa waveguide structure asymmetric active-MMI BLDs were fabricated on a single compact chip, with no refection coatings

Static characteristics

Flip-flop operation set-up

High speed flip-flop operation

Conclusion