Jj Juan José Vegas Olmos

Bidirectional radio-over-fiber link employing optical frequency multiplication

We propose a bidirectional radio-over-fiber link consisting of an optical downlink transmission employing the optical frequency multiplication principle, a remote local oscillator (LO) generation, a remote down-conversion of the radio-frequency uplink signals, and an optical uplink transmission employing intensity modulation-direct detection. Experiments demonstrate the optical up-conversion of 64-level quadrature amplitude modulated radio signals to 17.8 GHz after transmission over 4.4 km of multimode fiber, 12.5 and 25 km of single-mode fiber in the downlink; the uplink performance is evaluated in terms of down-conversion loss employing the optically generated LO.

Full-duplex single fiber transmission using FSK downstream and IM remote upstream Modulations for fiber-to-the-home

Full-duplex single fiber bidirectional transmission, using frequency-shift-keying modulation for downstream, by direct modulation of a tunable laser, and intensity modulation for upstream, in a wavelength-division-multiplexing passive optical access network is demonstrated. The optical network unit, located at the end user premises, reflects and orthogonally remodulates the received light. Rayleigh scattering effects are reported and analyzed. The system shows proper operation up to 1 Gb/s at 30-km reach.

Fiber-based broadband wireless access employing optical frequency multiplication

Employing optical frequency multiplication, we demonstrate experimentally the simultaneous delivery of different 64QAM radio signals at 5.8 and 17.7 GHz after 4.4 km of multimode fiber in a single radio-over-fiber link. We also propose a flexible mechanism for the dynamic radio link adaptation, and the simultaneous transmission of an in-band control channel with the wireless data channels for power control purposes at the antenna site is demonstrated experimentally

Simultaneous optical label erasure and insertion in a single wavelength conversion stage of combined FSK/IM modulated signals

We report on optical label swapping of combined frequency-shift keying/intensity modulation (FSK/IM) modulated signals by using a single wavelength conversion stage based on a semiconductor optical amplifier Mach-Zehnder interferometer. Simultaneous FSK label erasure and insertion at a bit rate of 156 Mb/s is successfully achieved for a 10-Gb/s IM payload with transmission over two spans of 40-km standard single-mode fiber.

Self-controlled all-optical label and payload separator for variable length bursts in a time-serial IM/DPSK scheme

We demonstrate an all-optical label and payload separator based on nonlinear polarization rotation in a semiconductor optical amplifier. The proposed scheme uses a variable packet length composed of a label and payload information signal modulated intensity modulation and differential phase-shift keying (DPSK) format, respectively. The separation is obtained by using the payload signal itself, exploiting the DPSK feature of being power constant, as a pumping light source. Therefore, the proposed scheme is asynchronous and does not need an external control signal.

Transmission of Microwave Signals beyond the Modal Bandwidth of Multimode Fiber Links

Employing the optical frequency multiplication method, we present an experimental performance analysis of the generation of microwave carriers up to 40 GHz and their transmission over a 4.4 km multimode fiber link. Also, 16 QAM and 64 QAM radio signals up to 20MS/s symbol rate are recovered successfully in the 24-30 GHz band after 4.4 km multimode fiber transmission, complying with the transmitter constellation error requirements of wireless standard IEEE 802.11a

All-optical FSK-WDM to intensity modulation-OTDM transmultiplexing for access passive optical networks

All-optical frequency shift keying (FSK)-WDM to intensity modulation (IM)-optical TDM (OTDM) transmultiplexing conversion by using a Mach-Zehnder interferometer wavelength converter is reported for an integrated access-metro network scenario. The WDM tributary signals are generated by direct FSK modulation on a grating coupler sampled reflector tunable laser. The resultant IM-OTDM signal is up to 20 times faster than with the tributary channels and is stable and tolerant to channel interference. All-optical demultiplexing has also been validated.

Optical label switched networks: laboratory trial and network emulator in the IST-STOLAS project

This article reviews the performance of an optical-label-controlled packet routing node as implemented in the European FP5-IST STOLAS project including a set of general engineering rules. Experimental networking scenarios and results from a STOLAS based network emulator supporting optical overspill routing are presented

In-band time-to-live signaling system for combined DPSK/SCM scheme in OLS

We propose and validate experimentally a time-to-live (TTL) signaling system for an optical label swapping scheme based on 10-Gb/s differential phase-shift-keying (DPSK) packets and with 100-Mb/s subcarrier multiplexing (SCM) label. The proposed scheme allows fast packet discarding by using a 3-GHz subcarrier tone. DPSK payload has only a 2.4-dB power penalty at 10/sup -9/ bit-error rate after superimposing the SCM and TTL labeling signal.

Improving the performance of a crosspoint-switch-based optical buffer by using a differential phase-shift keying payload

We experimentally demonstrate a novel decimal optical buffer scheme based on a multiloop configuration and a single switch element—an optical crosspoint switch (OXS) matrix. Its variable-delay range is of 1 to 999 times the basic delay unit. The buffer dynamic reconfiguration can be achieved at nanosecond switching speed. Our results show that by using a differential phase-shift keying (DPSK) payload in the buffer it can outperform an on-off keying payload with 4-dB sensitivity improvement owing to its alleviation of patterning-induced degradation, clearly validating DPSK as a promising modulation format to overcome nonlinear impairments and to extend number of hops in all-optical packet-switching network.