Jan Lamperski

Analysis of multiwavelength erbium-doped fiber ring source

In the presented work, we report the original numerical results of the properties of ring optical frequency comb generators employing the acousto optic frequency shifter (AOFS) and the single stable master laser (ML). A key element of the examined source is the AOFS controlled by the RF generator which determines frequency comb interval and stability. In each loop round-trip, AOFS splits the optical beam into two, where the deflected beam is frequency shifted. The multiple divisions, spectrum shifting and optical beam amplification in the ring configuration result in generating of an optical frequency comb. Performed numerical simulations allow spectral analysis of the generated optical frequency comb. We tested configurations with single and two cascaded AOFS operating at 1.5625 GHz. Calculations were carried out for a variety of input laser powers and different quantity of optical output frequencies whose number was controlled by an optical feedback filter bandwidth. It was shown that for different configurations and component parameters it was possible to obtain 20 - 30 uniform peaks with the amplitude difference of less than 0.5 dBm and OCNR in the range of 35-45 dB. We demonstrated that the main problem of the simultaneous multiwavelength fiber ring laser operation can be overcome by using a non resonant ring configuration with a quasi steady state operation. This method ensures generating of an optical comb with stable carrier frequency spacing. It allows diminishing the interchannel spacing and building up an ultra dense wavelength division multiplexing system.

Active fiber comb source with single and double frequency shifters for UDWDM applications

Numerical and experimental results of a multifrequency optical source with an exceptionally stable channel separation are presented. The system consists of a single master laser and a ring containing an acousto-optic frequency shifter and an optical amplifier. The operation is based on the multiple frequency shift every round trip. We tested a single and double frequency shifter configuration. For the single stage configuration up to 84 spectral lines with stable 1.5 GHz spacing were obtained. Experimental results of the system with two cascaded shifters were demonstrated for the first time and up to 30 optical carrier frequencies with 2.5 GHz channel separation were obtained. The experimental results were in agreement with numerical simulations.

Multifrequency source for UDWDM fiber systems

The numerical and experimental results of multifrequency optical source are presented. Up to 84 spectral lines with stable 1.5 GHz spacing ware obtained. The spectrum flatness was improved by equilizing polarization sensitivity of a frequency shifter.

Wavelength converting optical switch

The paper is devoted to the investigation of a fiber optic switch using a wavelength converter and an arrayed waveguide grating DWDM multiplexer. The principle of operation and a setup of a photonic part of the switch were presented. In the investigated switch, selection of a given optical output depends on the wavelength of operation of a tunable CW laser. The research of switch components properties (AWG multiplexer and wavelength converter basing on cross gain modulation effect in nonlinear SOA) was carried out. Simulations and measurements results of the optical switch for the signal at 2.488 Gbps bit rate were presented.

Application of UDWDM technology in FTTH networks

In the paper we presented results of investigation of an original ultra dense wavelength division technology based on optical comb generator and its implementation for FTTH networks. The optical comb generator used a ring configuration with an acousto-optic frequency shifter (AOFS) which ensured obtaining very stable optical carrier frequency distances. Properties of an optical comb generator module determined stability of the UDWDM transmitter. Key properties of a selective components based on all fiber Fabry-Perot resonant cavity were presented. Operation of direct and coherent detection DWDM systems were shown. New configurations of FTTH UDWDM architecture have been proposed.

UDWDM system with original tunable coherent receiver

In the paper we focus on problems of a coherent wavelength division multiplexing system with a gigahertz optical carrier frequency spacing generated by original optical comb source. We propose novel a receiver configuration of a coherent ultra dense WDM system (CoUDWDM) and compare features of a single photodiode and a balanced receiver design. The developed concept of a coherent receiver assumes selection of optical channels by the microwave section. We present simulation results of CoUDWDM system operation.

UDWDM system with optical multiwavelength source

In the presented paper we show a concept of the UDWDM system using multifrequency optical source with an acoustooptic frequency shifter as a key module. Original simulation results of the systems with very stable 3.125 and 6.25 GHz channel separation are presented.

Multifrequency erbium doped fiber source for UDWDM application

The original numerical and experimental results of multifrequency optical source, based on erbium doped fiber ring configuration are presented. Eleven spectral lines with very stable 1.5 GHz frequency separation were obtained. To achieve uniform amplitudes of optical frequencies, we propose an implementation of a polarization dependent diffraction efficiency equalizer of the acousto-optic shifter.

Spectral measurements of optical sources and optical components characteristics

This work is devoted to measuring spectral characteristics of narrowband optical sources, and passive and active transmittance of optical elements. The results obtained by using a Fabry-Perot interferometer, heterodyne and automated wavelength dependent loss measurements setups are presented.

Properties of active fiber optical sources

In the paper, we presented the results of the research on the properties of erbium doper fiber optical sources. We discussed properties and presented results of investigating single mode lasers, focusing on the problem of a beam oscillations at the radio frequencies range. An original method leading to the increase of power efficiency was described. We presented some methods and problems concerning multiwave sources with a special respect to resonant and nonresonant ring structures. We demonstrated results of investigation of a non resonant loop configuration with a quasi steady state operation free of RF components. Results of measuring mode-locked erbium ring lasers were shown.