Edith Garcia | Universidad Autonoma de Baja California (original) (raw)

Papers by Edith Garcia

Research paper thumbnail of <title>Simultaneous quadrature detection of suppressed-carrier weak-coherent-states using a homodyne optical Costas loop receiver</title>

Quantum Communications and Quantum Imaging IX, 2011

Weak coherent states (WCS) are being extensively employed in quantum communications and cryptogra... more Weak coherent states (WCS) are being extensively employed in quantum communications and cryptography at telecommunications wavelengths. For these low-photon-number applications, simultaneous field quadrature measurements are frequently required, such as in the detection of multilevel modulations in the communications scenario or in cryptographic applications employing continuous variables. For this task multiport balanced homodyne detection (BHD) structures are employed, based on the splitting of the received field into its (non-commutating) in-phase (I) and quadrature (Q) components and their separate beating with a local oscillator (LO) in two BHD. This allows the simultaneous measurements of the 2 quadratures at the price of an additional noise due to the vacuum fields that leak via the unused ports. These schemes require the proper optical phase synchronization between the LO and the incoming field, which constitutes a challenge for WCS reception, especially for suppressed carrier modulations that are required for power economy. For this task, a Costas loop is implemented for low photon number WCS, with the design of an optimum feedback scheme considering the phase diffusion of WCS generated by semiconductor lasers. We implemented an optical Costas loop at 1550 nm based on polarization splitting of the laser field to detect I and Q quadratures simultaneously. We present results on the performance in phase error and bit error rate and compare with corresponding quantum limit.

Research paper thumbnail of Detection of phase-diffused weak-coherent-states using an optical Costas loop

Optical Engineering, 2012

We describe a homodyne optical Costas loop receiver intended to detect weak coherent states with ... more We describe a homodyne optical Costas loop receiver intended to detect weak coherent states with diffused phase and suppressed carrier phase modulation. In order to get the information contained in the quadrature components of the optical field, we implement an 8-port receiver operating at 1550 nm, based on the manipulation of the state of polarization of both the local oscillator and the data signal. Employing binary phase-shift keying, we make measurements in the time and frequency domain of the quantum noise and bit error rate using an optimum loop filter, and compare the performance of our receiver against the standard quantum limit for the simultaneous quadrature detection, considering both ideal conditions and the overall efficiency of our set up.

Research paper thumbnail of Free-Space-Optical Quantum Key Distribution Systems: Challenges and Trends

Quantum Cryptography [Working Title], 2018

Nowadays, high security levels are required to transmit critical information for government, priv... more Nowadays, high security levels are required to transmit critical information for government, private and personal sectors. As a countermeasure, the Quantum Key Distribution systems are the best option in order to protect this information because it provides unconditional security. In addition, increasing the transmission distance is a highlight. Therefore, the Free-Space Optical Quantum Key Distribution systems (FSO-QKD) present an innovative way for sharing secure information between two parties located at ground stations, spacecraft or aircraft. However, these scenarios present several challenges regarding the hardware, protocols and techniques used that must be solved in order to enhance the performance parameters (security level, distance link, final secret key rate, among others) for any QKD system; although, in particular, a high transmission performance is required for both the classical and quantum channels. These issues impose the roadmap and trends in the research, academic and manufacturing sectors around the world.

Research paper thumbnail of The Convergence between Wireless Sensor Networks and the Internet of Things; Challenges and Perspectives: a Survey

IEEE Latin America Transactions, 2016

Research paper thumbnail of Mutual information in weak-coherent-state detection using a homodyne optical costas loop with different phase errors

Microwave and Optical Technology Letters, 2013

Research paper thumbnail of Phase-Locked Homodyne Measurement of Quasiprobability Q Function and Detection of Information-Carrying Weak-Coherent States

Microwave and Optical Technology Letters, 2013

ABSTRACT We present an eight-port homodyne receiver implemented in free space technology for dete... more ABSTRACT We present an eight-port homodyne receiver implemented in free space technology for detection of weak coherent states that carry binary information. For transmitted power economy, we use suppressed-carrier modulation, therefore, we have implemented an optical Costas-loop-type carrier synchronizer. We obtain the quasiprobability Q function from the in-phase and quadrature observables that are simultaneously measured. Statistical results for the quadrature components are presented. We perform measurements for the bit error rate and the mutual information between transmitter–receiver. The results show that the proposed setup is suitable in quantum communications and continuous variable quantum key distribution systems. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2431–2437, 2013

Research paper thumbnail of <title>Simultaneous quadrature detection of suppressed-carrier weak-coherent-states using a homodyne optical Costas loop receiver</title>

Quantum Communications and Quantum Imaging IX, 2011

Weak coherent states (WCS) are being extensively employed in quantum communications and cryptogra... more Weak coherent states (WCS) are being extensively employed in quantum communications and cryptography at telecommunications wavelengths. For these low-photon-number applications, simultaneous field quadrature measurements are frequently required, such as in the detection of multilevel modulations in the communications scenario or in cryptographic applications employing continuous variables. For this task multiport balanced homodyne detection (BHD) structures are employed, based on the splitting of the received field into its (non-commutating) in-phase (I) and quadrature (Q) components and their separate beating with a local oscillator (LO) in two BHD. This allows the simultaneous measurements of the 2 quadratures at the price of an additional noise due to the vacuum fields that leak via the unused ports. These schemes require the proper optical phase synchronization between the LO and the incoming field, which constitutes a challenge for WCS reception, especially for suppressed carrier modulations that are required for power economy. For this task, a Costas loop is implemented for low photon number WCS, with the design of an optimum feedback scheme considering the phase diffusion of WCS generated by semiconductor lasers. We implemented an optical Costas loop at 1550 nm based on polarization splitting of the laser field to detect I and Q quadratures simultaneously. We present results on the performance in phase error and bit error rate and compare with corresponding quantum limit.

Research paper thumbnail of Detection of phase-diffused weak-coherent-states using an optical Costas loop

Optical Engineering, 2012

We describe a homodyne optical Costas loop receiver intended to detect weak coherent states with ... more We describe a homodyne optical Costas loop receiver intended to detect weak coherent states with diffused phase and suppressed carrier phase modulation. In order to get the information contained in the quadrature components of the optical field, we implement an 8-port receiver operating at 1550 nm, based on the manipulation of the state of polarization of both the local oscillator and the data signal. Employing binary phase-shift keying, we make measurements in the time and frequency domain of the quantum noise and bit error rate using an optimum loop filter, and compare the performance of our receiver against the standard quantum limit for the simultaneous quadrature detection, considering both ideal conditions and the overall efficiency of our set up.

Research paper thumbnail of Free-Space-Optical Quantum Key Distribution Systems: Challenges and Trends

Quantum Cryptography [Working Title], 2018

Nowadays, high security levels are required to transmit critical information for government, priv... more Nowadays, high security levels are required to transmit critical information for government, private and personal sectors. As a countermeasure, the Quantum Key Distribution systems are the best option in order to protect this information because it provides unconditional security. In addition, increasing the transmission distance is a highlight. Therefore, the Free-Space Optical Quantum Key Distribution systems (FSO-QKD) present an innovative way for sharing secure information between two parties located at ground stations, spacecraft or aircraft. However, these scenarios present several challenges regarding the hardware, protocols and techniques used that must be solved in order to enhance the performance parameters (security level, distance link, final secret key rate, among others) for any QKD system; although, in particular, a high transmission performance is required for both the classical and quantum channels. These issues impose the roadmap and trends in the research, academic and manufacturing sectors around the world.

Research paper thumbnail of The Convergence between Wireless Sensor Networks and the Internet of Things; Challenges and Perspectives: a Survey

IEEE Latin America Transactions, 2016

Research paper thumbnail of Mutual information in weak-coherent-state detection using a homodyne optical costas loop with different phase errors

Microwave and Optical Technology Letters, 2013

Research paper thumbnail of Phase-Locked Homodyne Measurement of Quasiprobability Q Function and Detection of Information-Carrying Weak-Coherent States

Microwave and Optical Technology Letters, 2013

ABSTRACT We present an eight-port homodyne receiver implemented in free space technology for dete... more ABSTRACT We present an eight-port homodyne receiver implemented in free space technology for detection of weak coherent states that carry binary information. For transmitted power economy, we use suppressed-carrier modulation, therefore, we have implemented an optical Costas-loop-type carrier synchronizer. We obtain the quasiprobability Q function from the in-phase and quadrature observables that are simultaneously measured. Statistical results for the quadrature components are presented. We perform measurements for the bit error rate and the mutual information between transmitter–receiver. The results show that the proposed setup is suitable in quantum communications and continuous variable quantum key distribution systems. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2431–2437, 2013