Er-Yb Codoped Waveguide Amplifier Research Articles

Erbium-ytterbium co-doped aluminium oxide waveguide amplifiers fabricated by reactive co-sputtering and wet chemical etching.

We report on the fabrication and optical characterization of erbium-ytterbium co-doped aluminum oxide (Al2O3:Er3+:Yb3+) waveguides using low-cost, low-temperature deposition and etching steps. We deposited Al2O3:Er3+:Yb3+ films using reactive co-sputtering, with Er3+ and Yb3+ ion concentrations ranging from 1.4-1.6 × 1020 and 0.9-2.1 × 1020 ions/cm3, respectively. We etched ridge waveguides in 85% pure phosphoric acid at 60°C, allowing for structures with minimal polarization sensitivity and acceptable bend radius suitable for optical amplifiers and avoiding alternative etching chemistries which use hazardous gases. Scanning-electron-microscopy (SEM) and profilometry were used to assess the etch depth, sidewall roughness, and facet profile of the waveguides. The Al2O3:Er3+:Yb3+ films exhibit a background loss as low as 0.2 ± 0.1 dB/cm and the waveguide loss after structuring is determined to be 0.5 ± 0.3 dB/cm at 1640 nm. Internal net gain of 4.3 ± 0.9 dB is demonstrated at 1533 nm for a 3.0 cm long waveguide when pumped at 970 nm. The material system is promising moving forward for compact Er-Yb co-doped waveguide amplifiers and lasers on a low-cost silicon wafer-scale platform.

Er–Yb codoped waveguide/Raman hybrid optical amplifier with enhanced gain for DWDM system

A hybrid optical amplifier, using a combination of Er–Yb codoped waveguide amplifier (EYDWA) and Raman amplifier, is presented. The proposed scheme is investigated for 116 × 10 Gb / s dense wavelength-division multiplexed (DWDM) system at 0.2-nm channel spacing. The parameters are optimized using a hybrid genetic algorithm to achieve a flat gain of >25 dB, with a gain ripple of 2.78 dB. This is obtained over a wavelength range of 1539.7 to 1562.7 nm at 1 mW optimum input power per channel, without using any costly gain flattening scheme. An increase in gain ripple from 2.78 to 6.95 dB is observed for higher input powers up to 10 mW. The obtained noise figure (NF) is 10 dB) confirm the feasibility of the proposed amplifier for broadband long-haul DWDM systems.

Achieving high gain using Er-Yb codoped waveguide/fiber optical parametric hybrid amplifier for dense wavelength division multiplexed system

A hybrid optical amplifier is proposed using a combination of Er-Yb codoped waveguide amplifier (EYDWA) and fiber optical parametric amplifier (FOPA). The scheme is investigated for 100 × 40 Gb / s dense wavelength division multiplexed (DWDM) system at 0.2-nm channel spacing. The parameters are optimized to achieve a flat gain of >30.6 dB, with a gain ripple of 2.67 dB. This is obtained over a wavelength range of 1542 to 1562 nm at −10-dBm optimum input power per channel, without using any costly gain flattening scheme. For higher input powers up to 10 dBm, an increase in gain ripple from 2.67 to 6.13 dB is observed. The gain ripple of 2.67 dB of the proposed EYDWA–dual pump FOPA configuration is also much better than 10.32 dB for the hybrid EYDWA–single pump FOPA. The obtained high and flat gain, along with the low noise figure, confirms the usefulness of the proposed amplifier for applications in long-haul DWDM systems.

Novel Optical Flat-Gain Hybrid Amplifier for Dense Wavelength Division Multiplexed System

For the first time, a novel flat-gain optical amplifier is proposed using a hybrid configuration with an Er-Yb co-doped waveguide amplifier (EYDWA) and a semiconductor optical amplifier (SOA) for 100 × 10-Gb/s dense wavelength division multiplexed system at 0.2 nm interval. With an EYDWA-SOA hybrid amplifier, a flat gain of is obtained across the effective bandwidth with a gain variation of the order of 0.75 dB without using any gain clamping techniques. It is observed that when the proposed hybrid amplifier is used as a booster for hybrid distributed Raman amplifier and erbium doped fiber amplifier, the gain variation is reduced from 2.01 to ~ 1.15 dB efficiently with acceptable bit error rate.

116-fs soliton source based on an Er-Yb codoped waveguide amplifier

A passively mode-locked soliton ring fiber laser is investigated that utilizes a 4.5-cm erbium-ytterbium (Er-Yb) codoped waveguide amplifier as the gain element. The resulting short cavity (1.3 m of fiber) eliminates multipulsing behaviour and reduces the effects of resonant sidebands, enabling generation of 116-fs solitons with a pulse energy of 160 pJ at a fundamental repetition rate of 130 MHz.