Abstract: It is disclosed a optical transmitter for an optical network unit of a multi-wavelength passive optical network comprising an optical line termination and a number of further optical network units for transmitting upstream signals to said optical line termination on multiple upstream channels. The optical transmitter is configured to generate and transmit an optical activation signal carrying activation information to be transmitted to said optical line termination on an upstream channel, the activation signal having an optical power lower than the optical power of each one of said upstream signals. The optical transmitter comprises an optical source, a first electric source configured to modulate the optical source with a first electric signal carrying the activation information; and a second electric source configured to directly modulate the optical source with a second electric signal so as to produce a frequency chirp on the optical activation signal.

Abstract: A method for activating an ONU in a multi-wavelength PON. Other ONUs may be already active and transmit upstream signals to the OLT on various upstream channels. The new ONU transmits an activation signal superimposed to such upstream signals. Since the ONU may include an uncalibrated tunable transmitter, initially the activation signal wavelength might be different from that upon which the ONU shall be activated. The activation signal optical power is lower than the other upstream signals, so as not to impair their reception at the OLT. The OLT operates the ONUs already active on the upstream channel on which the new ONU shall be activated to suspend transmission for one or more time gaps, during which the OLT detects the activation signal. This improves activation signal detection conditions, thereby allowing to increase its bitrate. An acceptable duration of the activation procedure can then be achieved.

Abstract: It is disclosed a optical transmitter for an optical network unit of a multi-wavelength passive optical network comprising an optical line termination and a number of further optical network units for transmitting upstream signals to said optical line termination on multiple upstream channels. The optical transmitter is configured to generate and transmit an optical activation signal carrying activation information to be transmitted to said optical line termination on an upstream channel, the activation signal having an optical power lower than the optical power of each one of said upstream signals. The optical transmitter comprises an optical source, a first electric source configured to modulate the optical source with a first electric signal carrying the activation information; and a second electric source configured to directly modulate the optical source with a second electric signal so as to produce a frequency chirp on the optical activation signal.

Abstract: A method for activating an ONU in a multi-wavelength PON. Other ONUs may be already active and transmit upstream signals to the OLT on various upstream channels. The new ONU transmits an activation signal superimposed to such upstream signals. Since the ONU may include an uncalibrated tunable transmitter, initially the activation signal wavelength might be different from that upon which the ONU shall be activated. The activation signal optical power is lower than the other upstream signals, so as not to impair their reception at the OLT. The OLT operates the ONUs already active on the upstream channel on which the new ONU shall be activated to suspend transmission for one or more time gaps, during which the OLT detects the activation signal. This improves activation signal detection conditions, thereby allowing to increase its bitrate. An acceptable duration of the activation procedure can then be achieved.

Abstract: A media converter, a system and a method for converting packet based data into serial data and vice versa are provided. The media converter comprises a first interface configured to receive and provide a first type of data stream based on data packets, a second interface configured to receive and provide a second type of data stream based on a continuous serial bit stream, and a signal processor connected to the first and second interfaces and configured to convert said first type of data stream into said second type of data stream and vice versa on the basis of a block encoding/decoding algorithm and a line encoding/decoding algorithm. Thus, enhanced bit error rate may be obtained, thereby allowing the use of optical transmission channels of increased length.

Abstract: A media converter, a system and a method for converting packet based data into serial data and vice versa are provided. The media converter comprises a first interface configured to receive and provide a first type of data stream based on data packets, a second interface configured to receive and provide a second type of data stream based on a continuous serial bit stream, and a signal processor connected to the first and second interfaces and configured to convert said first type of data stream into said second type of data stream and vice versa on the basis of a block encoding/decoding algorithm and a line encoding/decoding algorithm. Thus, enhanced bit error rate may be obtained, thereby allowing the use of optical transmission channels of increased length.

Abstract: An optical phase locked loop (1), comprising an optical phase detector (2) receiving as inputs an optical signal to be locked (symbol I) and a locked optical signal (symbol II) and providing as its output an electrical error signal (VPD) indicating the phase shift existing between the optical signal to be locked (symbol I) and the locked optical signal (symbol II); an electrical loop filter (3) receiving the electrical error signal (VPD) and outputting a filtered electrical error signal (VPDF), and an optical voltage controlled oscillator (4) receiving as an input the filtered electrical error signal (VPDF) and outputting the locked optical signal (symbol II).

Abstract: An optical displacement transducer includes a transducing element comprising at least a first optical fiber, having a first end face substantially aligned along an axis and positioned with a small gap between said first end face and a second end face of a reception assembly, the transducer further comprising at least a light source coupled for transmission to first optical fiber and at least a photo-detector coupled for reception to the second optical fiber. The first end face and the second end face are displaceable along the axis and relatively with respect to each other, in order to follow the displacement of points associated to the first end face and second end face. The transducer is effective in detecting axial displacement simply and low cost.

Abstract: An optical displacement transducer includes a transducing element comprising at least a first optical fiber, having a first end face substantially aligned along an axis and positioned with a small gap between said first end face and a second end face of a reception assembly, the transducer further comprising at least a light source coupled for transmission to the first optical fiber and at least a photo-detector coupled for reception to the second optical fiber. The first end face and second end face are displaceable along the axis and relatively with respect to each other, in order to follow the displacement of points associated to the first end face and second end face. The transducer is effective in detecting axial displacement simply and at low cost.