Ardhendu Sekhar Patra

Bidirectional Transmission of 10 Gbit/s Using RSOA Based WDM-PON and Optical Carrier Suppression Scheme

Abstract We have proposed and demonstrated a novel architecture of cost effective bidirectional wavelength division multiplexed passive optical network (WDM-PON) system based on reflective semiconductor optical amplifier (RSOA), using optical carrier suppression (OCS) method. RSOA is employed at the user end to remodulate the downstream lightwave for uplink transmission. The OCS scheme is used to reduce the power loss of the signal during the transmission. A data rate of 10 Gbit/s is successfully transmitted over a single mode fiber (SMF) of more than 40 km length. The outstanding transmission performances at uplink and downlink have been observed by measuring the high Q factor and the sufficient low bit error rate (BER) at the BER tester.

RSOA-Based Full-Duplex WDM-PON for 20 Gbps Transmission in Two Channels Over a Long-Haul SMF Using External Modulation Scheme

Abstract We have proposed and demonstrated a full-duplex wavelength division multiplexed passive optical network (WDM-PON) configuration based on reflective semiconductor optical amplifier (RSOA). RSOA is used for reusing and remodulate the downlink signal in the uplink. We have used external modulation scheme for transmitting 20 Gbps data rates in two channels over a 40 km single mode fiber (SMF). The uplink and the downlink performances are checked by the bit error rate (BER) and the eye diagrams.

20 Gbps Bidirectional Transmission via Four Channels over Long-haul SMF in a WDM-PON Architecture using External Modulation Scheme

Abstract A novel architecture of bidirectional gigabit signal transport system over long-haul single-mode fiber (SMF) using wavelength division multiplexed passive optical network technique is proposed and demonstrated. In order to offer multimedia services of high bandwidth, four signals of 5 Gbps data rates are externally modulated and transmitted through four channels over 100-km SMF in uplink and downlink. In our proposed scheme, an excellent bit error rate, good Q-factor and clear eye diagrams are observed for both 100-km uplink and downlink transmission. This architecture has potential to transmit 4×5 Gbps over long-haul fiber backbone and it will be useful in future broadband communications.

40 Gbps Downstream Transmission Using DQPSK and 20 Gbps Upstream Transmission Using IRZ Modulation in Full-Duplex WDM-PON

Abstract A full duplex WDM-PON system is designed and demonstrated based on carrier reusing scheme and by employing differential quadrature phase shift keying (DQPSK) modulation in downlink and inverse return-to-zero modulation in the uplink to transmit 40 Gbps and 20Gbps data-rate respectively. Three Mach-Zehnder modulators are used sequentially to realize the 67 % carrier suppressed return to zero (CS-RZ) DQPSK modulation in the downlink transmission. Very low bit error rate values @10‒9 and clear eye-diagrams are observed over a 40 km single-mode-fiber transmission in our proposed full-duplex configuration.

Secure bidirectional transmission in a WDM-PON architecture employing RSOA-based remodulation scheme

A novel architecture of bidirectional wavelength division multiplexed passive optical network (WDM-PON), based on forward error correcting (FEC) scheme, has been proposed and analyzed theoretically. This configuration is made economical by employing injection locked Fabry-Perot laser diode (FPLD) for direct modulation at transmitter end and reflective semiconductor optical amplifier (RSOA) as remodulator at receiver end. Reed-Solomon (RS) codec is preferred in the design to comprehend the FEC scheme. The RS (255, 251) codec is realized by field-programmablegate- array (FPGA) with the help of VERILOG programming. Excellent transmission performances of 10 Gbps datasignal over maximum of 20 km SMF in downlink and uplink are obtained by the low bit error rate (BER) values and significant eye diagrams at BER analyzer.

Radio-over-fiber transport system employing free-space optical communication scheme with parabolic reflector

A bidirectional radio over fiber (ROF) transport system in combination with optical free space transmission schemes based on WDM, external light injection and optical add-drop multiplexing techniques is proposed and demonstrated. A diverging lens at the fiber end and a parabolic reflector at the receiver end are designed to employ optical free space transmission scheme in the configuration which transmits data-stream of 1~10 Gbps at 12.5 GHz. Excellent BER values and impressive eye diagrams for both down/uplink have shown that our proposed system is convenient and suitable for 80 km optical and 10 m optical free space transmission.

Bidirectional and simultaneous FTTX/Ethernet services using RSOA based remodulation and polarization multiplexing technique

A bidirectional and simultaneous transmission of Ethernet, FTTX services through single optical carrier wavelength employing polarization multiplexing technique in the transmitter end and the user end. 10 Gbps and 2.5 Gbps datarates are transmitted over 50 km single mode fiber employing POLMUX technique at OLT and ONU to provide Ethernet and FTTX services concurrently to the user. Reflective semiconductor optical amplifier is used to reuse and remodulate the downlink signal to uplink transmission. The upstream and the downstream transmission performances are observed by the bit error rate values and the eye diagrams obtained by the BER analyzer.

80 channels HDTV signal transmission using optical carrier suppression scheme and injection-locked FPLDs

A bidirectional ROF configuration has been proposed and developed to transmit 80 channels HDTV signal over 80 km SMF integrating mutually injection locking, optical carrier suppression (OCS) and remodulation techniques. LiNbO3 Mach-Zehnder modulator is used at transmitter end to realize the OCS scheme by mixing two complementary signals of 30GHz. RSOA is deployed at the user end to reuse and remodulate the downstream HDTV signal to upstream transportation over same 80km fiber link. The uplink and downlink transmission performances are observed and analyzed by excellent eye-diagram and low bit error rate values.

Full-duplex transmission of FTTX/ethernet services in a RSOA based WDM-PON architecture using polarization multiplexing technique

In this paper a simple architecture has been developed for full-duplex transmission of different services like Ethernet, FTTX etc through single optical carrier wavelength employing polarization multiplexing technique in the transmitter end and the user end simultaneously. 10 Gbps and 2.5 Gbps datarates are bidirectionally transported over 50 km single mode fiber (SMF) to provide Ethernet and FTTX services concurrently to the user. Reflective semiconductor optical amplifier (RSOA) is used to reuse and remodulate the downlink signal to uplink transmission. The upstream and the downstream transmission performances are observed by the bit error rate (BER) values and the eye diagrams obtained by the BER analyzer at both ends.

A RSOA based full-duplex 80 channel CATV signal with 1.25 Gbps data-stream transmission system using optical carrier suppression and injection-locked FPLDs

In this paper a novel architecture has been proposed and developed for full-duplex transmission of 80 channel CATV signal over 80 km single mode fiber (SMF) using various techniques such as mutually injection locking, optical carrier suppression (OCS) and remodulation etc. The up/downlink transmission performances are observed by the low bit error rate (BER) values and impressive eye diagrams. The satisfactory values of CNR, CBT and CSO verify the successful transmission of CATV signals through our proposed configuration.