All-optical wavelength conversion in SOA-based Mach–Zehnder interferometer with monolithically integrated loss-coupled DFB laser diode

Abstract

We demonstrated monolithic integration of a continuous wave probe source consisting of a loss-coupled distributed feedback laser diode (DFB LD) and a Mach-Zehnder interferometric wavelength converter. The integrated device was fabricated using a modified buried ridge stripe (BRS) structure with an undoped InP clad layer on the top of a passive waveguide to reduce high propagation loss. A propagation loss in the passive waveguide as low as 5.29 ± 0.92 dB cm −1 was achieved. For the first time, wavelength conversion at 10 Gb s −1 was achieved with an extinction ratio of 7 dB and a power penalty of 2.8 dB at a 10 −9 bit error rate. The proposed BRS structure is very useful for fabrication of photonic integrated circuits consisting of monolithic integration of active and passive waveguides.

Improvement of the dynamic input power range in a 10 Gb s−1all-optical Mach–Zehnder interferometric wavelength converter module with monolithically integrated SOA preamplifiers and tapered-edge multimode interference couplers

“…The lateral structure of MZI-WC consisted of a modified buried ridge stripe (BRS) structure with an undoped InP clad layer on the top of the passive waveguide to reduce the high propagation loss. The precise fabrication process was described previously [7]. This process has advantages of achieving a low propagation loss in the passive waveguide, good uniformity and moderate current blocking in the active region [7,8].…”

“…Crossphase modulation (XPM) schemes in semiconductor optical amplifiers (SOAs) are a promising candidate for an all-optical wavelength conversion application, because they provide an extinction ratio enhancement for both wavelength down-and up-conversions, high-speed operation, low chirping and high conversion efficiency [2]. Several groups reported SOA-based integrated Michelson (MI) or Mach-Zehnder interferometric (MZI) wavelength converters [3][4][5][6][7][8][9][10][11][12]. However, one problem of the interferometric wavelength converter is a relative small input power dynamic range of about 3-4 dB at 10 Gb s −1 due to its periodic transfer response [5].…”

“…The non-uniformity of the MZI-WC on a wafer is one of the major bottlenecks in realizing low cost. In particular, the problem of non-uniformity in the MZI-WC with Y-branch often occurs due to difficulties in obtaining fine patterns at the y-junction using conventional photolithography, developing and reactive ion etching (RIE) [7,9]. Thus, multimode interference couplers (MMIs) are already widely incorporated in several PICs such as MZI-WCs, Michelson interferometer WCs and LD-gate switches for the realization of wavelength division multiplexing applications because of a stable splitting ratio, compact size, good fabrication tolerance, insensitivity to wavelength and polarization [13].…”

Optimising negative chirp of an electroabsorption modulator for use in high‐speed optical networks

“…With appropriate dispersion management using either dispersion compensated fiber and/or dispersion shifted fiber this span can normally be extended into regions above 100 km when amplification becomes important [12]. Therefore the majority of the transmission experiments that incorporate EAMs utilise some kind of dispersion management to compensate loss due to large frequency chirp and this is considered to be the weakest point in the use of external EAMs [13]. However, zero chirp or reduced chirp (i.e.…”

Chirp Control of an Electroabsorption Modulator to be used for Regeneration and Wavelength Conversion at 40 Gbit/s in All-Optical Networking

“…An EAM possesses faster absorption recovery time (i.e., less than 10 ps) and also experiences reduced chirp on the output signal (ideally zero or negative) as compared to other optical devices (e.g., semiconductor optical amplifiers) [20][21][22][23]. Furthermore, it has been suggested that an EAM is (theoretically) capable of handling tera-hertz modulation rates [24].…”