Abstract: An optical signal amplifier using a praseodymium doped fiber is described. The optical signal amplifier includes a signal laser, a first optical isolator, a second optical isolator a pump laser, a wave division multiplexer, a silica based glass optical fiber, a second optical isolator, an optical power meter, and an optical spectrum analyzer (OSA). The signal laser generates a signal laser beam. The pump laser generates a pumped laser beam. The wave division multiplexer combines the signal laser beam and the pumped laser beam and generates a combined laser beam. The silica based glass optical fiber has a preferred concentration of praseodymium ions of about 50×1024 ions/m3 and a length of about 5.7 m. The silica based glass optical fiber receives the combined laser beam, amplifies photons in the combined laser beam, and generates an amplified laser beam.

Abstract: A body area network (BAN) architecture including a plurality of ultra-wideband (UWB) BAN node devices, a control node device, and a remote node device is described. The plurality of UWB BAN node devices measures real-time physiological data of a patient and transmits the physiological data to the control node device using UWB signals. The control node device encodes the UWB signals using an spectral amplitude coding-optical code division multiple access (SAC-OCDMA) encoder, modulates the encoded UWB signals using an on-off keying (OOK) scheme, combines the modulated UWB signals into an optical signal using an optical coupler, and transmits the combined optical signal through a free space optical (FSO) link to the remote node device. The remote node device decodes the combined optical signal using an SAC-OCDMA decoder, converts the decoded optical signal into an electrical signal, and analyzes the physiological data based on the electrical signal.

Abstract: A method and system for regenerating free space optical (FSO) signal pulses over free space optical (FSO) links. The FSO signal pulses are received over a first FSO link by a receiver telescope. The FSO signal pulses are split into a first part and a second part. The first part of the FSO signal pulses is converted to an electrical signal. The electrical signal is low pass filtered, amplified, and inverted to generate a negative electric voltage. The amplitude of the second part of the FSO signal pulses is attenuated by an optical absorber based on the negative electric voltage, thus regenerating the FSO signal pulses. The regenerated FSO signal pulses are amplified and bandpass filtered. The amplified and filtered regenerated FSO signal pulses are transmitted on a second FSO link.

Abstract: An apparatus for determining unknown radio frequencies is described. The apparatus modulates a first optical signal from tunable optical source with RF signal that includes unknown center frequency value to generate modulated optical signal. The apparatus combines modulated optical signal with second optical signal to generate combined modulated optical signal. The apparatus receives output electrical signal from photodetector in response to receiving combined modulated optical signal at photodetector, splits output electrical signal into first output electrical signal and second output electrical signal, and filter first output electrical signal by applying first optical bandpass filter centered to generate first filtered RF signal. The apparatus tunes tunable optical source to first beat frequency value to determine unknown frequency value of RF signal.