Design and Simulation of Photonic Devices and Circuits

Design and Simulation of Photonic Devices and Circuits

Objectives • To introduce the basic physics of photonic devices and apply it for the design of optical transmission systems and networks. • To simulate the various photonic components and also to do system level simulations. • To study different noise processes in photonic circuits and understand their impact on Q-factor or BER. • To develop engineering rules for the photonic circuit design.

Expectations • My expectation: – Speak up. – Course as interactive as possible. • Your expectations ?

Point-to-Point Optical Transmission System Lasers Modulators MUX Fiber Amp DEMUX Rx

Course Outline • Modulation and transmission of light – 6 hours/3 lectures. (Device behavior models with focus on the terminal performance. ) – Sec. 1 Optical Modulators – Sec. 2 Optical Fibers • Generation, amplification and detection of light - 6 hours/ 4 lectures – Sec. 3 Semiconductor lasers and LED – Sec. 4 Amplifiers (SOA, EDFA and Raman) – Sec. 5 Photo-detectors

Course Outline Point-to-point, single wavelength transmission system (6 hours/2 lectures) Sec. 6 Functional Block (Tranmitter and Receiver) Design Sec. 7 Penalties due to fiber dispersion and amplifier noise Sec. 8 System design with Tx, fiber, concatenated amplifiers and Rx Eye Diagrams and Q-factor estimation Wavelength division multiplexed system (2 hours/1 lecture) Sec. 9 Add/drop multiplexers Sec. 10 cross-talk in WDM system Linear cross-talk Nonlinear cross-talk due to four wave mixing Optical Networks (2 hours/1 lectures) Sec. 11 - SONET/SDH, circuit, packet and cell networks

Schedule • • • Jan 6 – Lecture - Introduction Jan 13 – Lecture - Sec. 1 Jan 20 – Lecture - Sec. 2 Jan 27 - Lecture - Sec. 2 Feb. 3 - Lecture - Sec. 3 Feb 10 - Lecture Sec 3 & 4 Feb 17 - Lecture Sec 4 &5 Feb 24 - Lecture Sec 5 March 2 - Lecture Sec 6 &7

Schedule • • March 9 Lecture Sec 7&8 March 16 Lecture Sec. 9 &10 March 23 Lecture Sec. 11 March 30 Lecture Review

Assessment • Final exam – 65% • Project - 35% – Each student will be assigned a project. – The project involves • A good research survey. • Simulation of a photonic device or a circuit. • Project report.

History • Invention of Laser and Maser in 1960 s - In 1950 s, Townes and Schawlow in the US and Basov and Prochorov in the USSR proposed to make use of stimulated emission for the construction of coherent optical sources. – In 1960 - Maiman demonstrated the first laser. – In 1970, Hayashi et al demonstrated Ga. As semiconductor laser operating at room temperature. • Low Loss Fibers in 1970 s – Fibers available in 1960 s had losses in excess of 1000 d. B/km. – In 1970, Kapran, Keck and Maurer invented a low loss fiber with the loss of 20 d. B/km. – In 1979, Miya et al reported a loss of 0. 2 d. B/km near 1550 nm. • Erbium Doped Fiber Amplifiers in 1980 s. – In 1980 s, Poole et al in the UK and Desuvire in the US demonstrated light amplification by EDFA. Now it is used in all commercial long haul fiber optic networks.

The Evolution of Fiber Optic Systems • First generation operated around 850 nm. Bit rate 45 -140 Mb/s. Ga. As-based optical souces, multimode fibers and silicon detectors. • Second generation at 1300 nm. Substantial increase in transmission distance and bit rate (622 Mb/s-2. 5 Gb/s). Both multimode and single mode fibers were used.

The Evolution of Fiber Optic Systems • Third generation systems operated around 1550 nm since the fiber loss @ 1550 nm is the lowest. But standard fibers have larger dispersion at 1550 nm than at 1300 nm. Fiber manufacturers overcame this limitation by inventing dispersion shifted (DS) fibers. Transmission rates – 2. 5 Gb/s to 10 Gb/s. • Invention of (Erbium Doped Fiber Amplifier) EDFA revolutionized light wave communication. Wavelength Division Multiplexing (WDM) offered a further boost in transmission capacity Fourth generation systems operated at 1550 nm with EDFA and WDM

The Evolution of Fiber Optic Systems • With the advent of WDM, it was realized that DS fibers were not suitable for long haul transmission because of four wave mixing among different channels of WDM. So, standard fiber (D=17 ps/nm. km) or Non-zero dispersion shifted fiber (NZDSF) are used in current commercial systems. Relatively large dispersion of these fibers is compensated by means of dispersion compensating fibers. • Large local dispersion helps to minimize four wave mixing penalty in WDM systems.

Modulation Formats • Traditionally non-return-to-zero (NRZ) format is used in optical communication systems. • Recently, quasi-linear return-to-zero (RZ), solitons, carriersuppressed RZ (CS-RZ) and differential phase shift keying (DPSK) have drawn considerable attention. • Soliton is a pulse that propagates without change in shape. When the fiber dispersion is balanced by nonlinearity, solitons are formed. Solton is a special case of RZ format. • NRZ requires smaller signal bandwidth as compared to RZ because on-off transitions occur fewer times.

Contact Info • Instructor: Dr. S. Kumar • E-mail: kumars@mail. ece. mcmaster. ca • Office hours: Monday 2: 30 to 5: 00. Tuesday 4: 00 to 5: 00 • Office: CRL #204 • Web page of the course: www. ece. mcmaster. ca/faculty/~kumars/Lightwave_course. htm