Abstract:
An optically powered media conversion device for performing optical to electrical conversion is disclosed. The conversion device includes at least one optical coupler for receiving at least one optical signal comprising at least one wavelength, wherein the at least one optical coupler extracts energy from the at least one optical signal, and at least one detector for extracting data from the at least one optical signal and converting the optical signal to an electrical signal using a photovoltaic process. The conversion device further includes a transmitter for converting an electrical signal to an optical signal and transmitting the optical signal to a first device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of application Ser. No. 14/206,986, filed Mar. 12, 2014, which application claims priority from U.S. Provisional Patent Application No. 61/778,109, filed Mar. 12, 2013, which applications are incorporated herein by reference in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to management of optical signal distribution. In particular, the present application relates to an optically powered media converter. 
       BACKGROUND 
       [0003]    Applications using fiber optics require the use of external media converters to convert optical signals to electrical signals and to convert electrical signals to optical signals. These media converters require power to perform this conversion, and often receive power from external devices such as a computer, keyboard, USB port, or an AC-DC power supply that is plugged into a wall outlet. However, using an AC-DC power supply can create problems by introducing electromagnetic interference to the optical signal. Additionally, media conversion devices may be placed in locations far from these external power sources, thereby making it difficult or impractical to route power to such locations. 
       SUMMARY 
       [0004]    In general terms, this disclosure is directed to optically powered media converters. In one possible configuration and by non-limiting example, optically powered media converters are powered by extracting energy from an optical signal and an electrical signal. 
         [0005]    One aspect of the present disclosure relates to a method of providing power to a remote optical conversion device the method comprising receiving an optical signal at an optical interface of an electrical to optical interface device, wherein the optical signal is delivered to the optical interface via a fiber optical cable and includes at least one wavelength. The method further comprises extracting energy from the optical signal and developing electrical current from the energy using a photodetector, wherein the electrical current is developed through a photovoltaic process. The method further comprises extracting information from the optical signal and transmitting information via an electrical interface of the electrical to optical interface device. 
         [0006]    Another aspect of the present disclosure relates to a system for providing power to a remote conversion device, wherein the system comprises a first and a second device, wherein the first device includes an optical source and wherein the second device includes electrical data. The system further comprises a media conversion device and at least one optical fiber cable having a first end and a second end, wherein the first end is connected to the first device and the second end is connected to the media conversion device. Additionally, the system comprises at least one electrical conductor cable having a first end and a second end, wherein the first end is connected to the second device and the second end is connected to the media conversion device. 
         [0007]    Another aspect of the present disclosure relates to an optically powered media conversion device for performing optical to electrical conversion, wherein the optically powered media conversion device comprises at least one optical coupler for receiving at least one optical signal comprising at least one wavelength, wherein the at least one optical coupler extracts energy from the at least one optical signal. The optically powered media conversion device further comprises at least one detector for extracting data from the at least one optical signal and converting the optical signal to an electrical signal using a photovoltaic process. Additionally, the optically powered media conversion device comprises a transmitter for converting an electrical signal to an optical signal and transmitting the optical signal to a first device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic block diagram of a system using an optically powered media converter and sensor in accordance with the present disclosure. 
           [0009]      FIG. 2  is an embodiment of an optically powered media converter shown in  FIG. 1 . 
           [0010]      FIG. 3  is an alternative embodiment of an optically powered media converter shown in  FIG. 1 . 
           [0011]      FIG. 4  is an alternative embodiment of an optically powered media converter shown in  FIG. 1 . 
           [0012]      FIG. 5  is an alternative embodiment of an optically powered media converter, as shown in  FIG. 1 , with an embedded charge pump. 
           [0013]      FIG. 6  is an embodiment of an optically powered media converter, as shown in  FIG. 1 , with an embedded charge pump, microcontroller, and a temperature sensor. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Various embodiments will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims. 
         [0015]    The present disclosure relates to an optically powered media converter wherein the media converter is a standalone device located externally to the communicating devices. The present disclosure describes several embodiments for providing optical power to the remotely located media converter. In each embodiment of the present disclosure, the externally located media converter extracts optical energy from an inbound optical signal, which eliminates the need for an independent electrical power source. In some examples described herein, a media converter can include a device with a receiver used to detect and convert optical signals to signals of a different format (e.g., electrical signals) and optionally a transmitter used to convert signals of that different format to optical signals. 
         [0016]    In some embodiments, the externally located media converter requires little power because it does not include an optical source such as a fiber optic grade light emitting diode (LED), a vertical cavity semiconductor laser (VCSEL), a Fabry-Pérot laser, or a distributed feedback laser. In such an embodiment, the media converter modulates a previously received optical signal with an electrical signal including data desired for optical transmission. In other embodiments, the externally located media converter includes an optical source such as low lasing threshold current VCSEL that is powered by a charge pump within the media converter. In such an embodiment, the media converter may use anywhere between 1 to 5 mW of power. 
         [0017]    Referring now to  FIG. 1 , a schematic block diagram of a system using an optically powered media converter and sensor in accordance with the present disclosure is shown. In this example, the system  100  includes a media converter  102 , a first device  104 , a second device  106 , at least one optical fiber  108 , and at least one electrical conductor  110 . In this example, the first device contains an internal AC-DC power supply (not shown) that is powered by an external power supply  112  using a power cable  114 . The first device also includes an optical transmitter capable of generating an optical signal. Examples of optical transmitters useable in the first device include LEDs, Fabry-Pérot lasers, distributed feedback lasers, and VCSELs. In this embodiment, the first device  104  transmits the generated optical signal including information and sufficient optical power over the optical fiber  108 , wherein the optical signal including information is converted to an electrical signal and optical energy is extracted by the externally located media converter  102 . The media converter  102  then transmits the electrical signal over an electrical conductor  110  to the second device  106 . Types of electrical conductors that can be used are copper cable or unshielded twisted pair. Alternatively, other types of conductive cable is used. Example embodiments of the media converter  102  are described in more detail with reference to  FIGS. 2-6 . 
         [0018]    Referring now to  FIG. 2 , an example embodiment of an optically powered media converter  200  is shown. In various embodiments, the optically powered media converter  200  can be used in an optical-electrical communication arrangement, such as in the system  100  of  FIG. 1  (e.g., as an optically powered media converter  102 ). The media converter  102  includes first and second optical couplers  202  and  204 , respectively, a photodetector  206 , and a transmitter  208 . In this embodiment, the first device  104  generates an optical signal with a single wavelength and with sufficient power to drive the receive function of the media converter  102 . The first coupler  202  within the media converter  102  extracts energy from the optical signal and delivers the energy to drive the photodetector  206 . Using the power from the optical signal, the photodetector  206  extracts data from the optical signal and converts the optical signal into an electrical signal using a photovoltaic process. In some embodiments, an LED is used as a photodetector. The photodetector then transmits the electrical signal to the second device  106 , located externally to the media converter  200 , over the electrical conductor  110 . 
         [0019]    The transmitter  208  part of the media converter  102  accepts electrical signals from the second device  106  through the electrical conductor  112  and extracts sufficient energy from the electrical conductor  112  to drive a switch and a modulator that is used to modulate the residual optical signal with the electrical signal. Protocols such as Ethernet drive the electrical conductor  112  with sufficient energy to drive a switch and a modulator. In some embodiments, a microelectromechanical systems (MEMS) switch is used. In some embodiments, a cavity or an interferometer is used as a modulator. The modulated optical signal is then coupled onto the optical fiber  108  using the second coupler  204  and transmitted back to the first device  104 . Because the optical fiber  108  transmits or receives one optical signal at a time, this first embodiment of the present disclosure operates as a half-duplex system, or utilizes a polarization scheme to enable duplex operation. 
         [0020]    Referring now to  FIG. 3 , an example of an optically powered media converter  300  is shown. In various embodiments, the optically powered media converter  300  can be used in an optical-electrical communication arrangement, such as in the system  100  of  FIG. 1  (e.g., as an optically powered media converter  102 ). The media converter  300  includes first and second optical couplers  308  and  310 , respectively, a photodetector  312 , and a transmitter  314 . In this embodiment, the first device  302  generates a first and a second optical signal at different wavelengths that are combined using a wave division multiplexer  304  and transmitted over the optical fiber  306 . The first coupler  308  within the media converter  300  extracts energy from the second optical signal and delivers the energy to drive the photodetector  312 . Using the generated power, the photodetector  312  extracts data from the second optical signal and converts the second optical signal into an electrical signal using a photovoltaic process. The photodetector  312  then transmits the electrical signal to the second device  106 , located externally to the media converter  300 , over the electrical conductor  110 . 
         [0021]    The transmitter  314  part of the media converter  300  accepts electrical signals from the second device  106  through the electrical conductor  112  and extracts sufficient energy from the electrical conductor  112  to drive a switch and a modulator that is used to modulate the first optical signal with the electrical signal. Protocols such as Ethernet drive the electrical conductor  112  with sufficient energy to drive a switch and a modulator. In some embodiments, a MEMS switch is used. In some embodiments, a cavity or an interferometer is used as a modulator. The first optical signal is modulated with the electrical signal and is then coupled onto the optical fiber  306  using the second coupler  310  and transmitted back to the first device  302 . Because the optical fiber  306  can simultaneously transmit and receive two optical signals, this embodiment of the present disclosure operates as a full-duplex system. 
         [0022]    Referring now to  FIG. 4 , an example of an optically powered media converter  400  is shown. In various embodiments, the optically powered media converter  400  can be used in an optical-electrical communication arrangement, such as in the system  100  of  FIG. 1  (e.g., as an optically powered media converter  102 ). The media converter  400  includes first and second optical couplers  408  and  410 , respectively, a photodetector  412 , a transmitter  414 , and a power converter  416 . In this embodiment, the first device  402  generates a first and a second optical signal at different wavelengths that are combined using a wave division multiplexer  404  and transmitted over the optical fiber  406 . The first coupler  408  within the media converter  400  extracts part of the energy from the second wavelength and delivers the energy to a power converter  416  that uses the energy to develop electrical current using a photovoltaic process. This electrical power is used by the entire system. 
         [0023]    Additionally, the first coupler  408  extracts the energy from the first wavelength and delivers it to power the photodetector  412 . The photodetector  412  then extracts data from the first wavelength and converts the optical signal into an electrical signal using a photovoltaic process. The photodetector  412  then transmits the electrical signal to the second device  106 , located externally to the media converter  400 , over the electrical conductor  110 . 
         [0024]    The transmitter  414  part of the media converter  400  accepts electrical signals from the second device  106  through the electrical conductor  112  and power generated by the power converter  416  to drive a switch and a modulator. In some embodiments, a MEMS switch is used. In some embodiments, a cavity or an interferometer is used as a modulator. The second optical signal is modulated with the electrical signal and is then coupled onto the optical fiber  406  using the second coupler  410  and transmitted back to the first device  402 . Because the optical fiber  406  can simultaneously transmit and receive two optical signals, this embodiment of the present disclosure operates as a full-duplex system. 
         [0025]    Referring now to  FIG. 5 , an example embodiment of an optically powered media converter  500  using discrete transmit and receive optical fibers  504  and  506 , respectively, is shown. In various embodiments, the optically powered media converter  500  can be used in an optical-electrical communication arrangement, such as in the system  100  of  FIG. 1  (e.g., as an optically powered media converter  102 ). The media converter  500  includes a splitter  508 , a photovoltaic cell  510 , a charge pump  512 , a storage device  514 , a PIN detector  516 , a first driver  518 , a second driver  520 , and an optical transmitter  522 . In this embodiment, the first device  502  transmits an optical signal containing power and data over the transmit optical fiber  504 . The optical signal terminates at a splitter  508  in the media converter  500  wherein the splitter  508  divides part of the energy to a PIN detector  516  for data extraction and sends the remaining part to a photovoltaic cell  510  for power extraction. In some embodiments, the splitter  508  evenly divides the signal power between to the PIN detector  516  and the photovoltaic cell  510 . In other embodiments, the splitter  508  divides the signal in other ratios wherein the higher side is used for power. 
         [0026]    The PIN detector  516  is used to extract data from the first wavelength. The PIN detector  516  outputs the data as an electrical signal that is transmitted to the second device  106 , located externally to the media converter  500 , over the electrical conductor  110  using the first driver  518 . In other embodiments, the electrical signal is transmitted to the second device  106  using a PHY device such as an Ethernet PHY chip. 
         [0027]    As described above, the photovoltaic cell  510  receives a divided signal from the splitter  508  and extracts power therefrom. The photovoltaic cell  610  powers a charge pump  512  that generates a higher voltage than the incoming supply voltage using one or more capacitors. The charge pump  512  regulates the current supplied to the storage device  514  thereby enabling the storage device  514  to store energy that is then used by the media converter  500 . In some embodiments, a super capacitor is used as the storage device  514 . In other embodiments a battery is used. In some embodiments, the storage device  514  is factory pre-charged and in other embodiments, the storage device is not pre-charged. 
         [0028]    The media converter  500  also sends an optical signal carrying data from an electrical signal generated by the second device  106  to the first device  104  over the receive optical fiber  506 . In this embodiment, an optical signal is generated by an optical transmitter  522 . Examples of an optical transmitter used by the media converter  500  are an LED, a Fabry-Pérot laser, a distributed feedback laser, or a VCSEL. In this embodiment, the optical transmitter  522  is driven by a driver  520  with the electrical signal transmitted from the second device  106  as the input signal. The generated optical signal including information from the electrical signal is then transmitted to the first device  502  over the receive optical fiber  506 . Because the transmit and receive optical fibers  504  and  506 , respectively, can simultaneously transmit and receive two optical signals, this embodiment of the present disclosure operates as a full-duplex communication system. 
         [0029]    Referring now to  FIG. 6 , an example embodiment of an optically powered media converter  600  using discrete transmit and receive optical fibers  604  and  606 , respectively, is shown. In various embodiments, the optically powered media converter  600  can be used in an optical-electrical communication arrangement, such as in the system  100  of  FIG. 1  (e.g., as an optically powered media converter  102 ). The media converter  600  includes a splitter  608 , a photovoltaic cell  610 , a charge pump  612 , a storage device  614 , a PIN detector  616 , a microcontroller  618 , a temperature sensor  620 , and an optical transmitter  622 . In this embodiment, the first device  602  transmits an optical signal containing power and data over the transmit optical fiber  604 . The optical signal terminates at a splitter  608  in the media converter  600  wherein the splitter  608  divides part of the energy to a PIN detector  616  for data extraction and sends the remaining part to a photovoltaic cell  610  for power extraction. In some embodiments, the splitter  608  evenly divides the signal power between to the PIN detector  616  and the photovoltaic cell  610 . In other embodiments, the splitter  608  divides the signal in other ratios wherein the higher side is used for power. 
         [0030]    The PIN detector  616  and built-in amplifiers in the microcontroller  618  extract data from the first wavelength. The microcontroller  618  outputs the data as an electrical signal on a general purpose input/output pin and transmits the electrical signal to the second device  106 , located externally to the media converter  600 , over the electrical conductor  110 . 
         [0031]    As described above, the photovoltaic cell  510  receives a divided optical signal from the splitter  508  and extracts power therefrom. The photovoltaic cell  610  powers a charge pump  612  that generates a higher voltage than the incoming supply voltage using one or more capacitors. The charge pump  612  regulates the current supplied to the storage device  614  thereby enabling the storage device  614  to store energy that is then used by the media converter  600 . In some embodiments, a super capacitor is used as the storage device  614 . In other embodiments a battery is used. In some embodiments, the storage device  614  is factory pre-charged and in other embodiments, the storage device is not pre-charged. 
         [0032]    In this embodiment, the media converter  600  also sends an optical signal carrying data from an electrical signal generated by the second device  106  and temperature data generated by the temperature sensor  620  to the first device  602 . In this embodiment, the microcontroller  618  receives data from the first device  106  and the embedded temperature sensor  620 . Alternatively, the temperature sensor  620  is located externally to the media converter  600  in other embodiments. An optical transmitter  622  that is driven by the microcontroller  618  generates an optical signal. Examples of an optical transmitter  622  used by the media converter  600  are a VCSEL, an LED, a Fabry-Pérot laser, or a distributed feedback laser. In this embodiment, a VCSEL is used as the optical transmitter  622  due to its low lasing threshold current, allowing the microcontroller  618  to drive the VCSEL using a general purpose input/output pin. The generated optical signal is then transmitted to the first device  602  over the receive optical fiber  606 . Because the transmit and receive optical fibers  604  and  606 , respectively, can simultaneously transmit and receive two optical signals, this embodiment of the present disclosure operates as a full-duplex communication system. 
         [0033]    The various embodiments described above are provided by way of illustration only and should not be construed to limit the claims attached hereto. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the following claims.