# ECE 456

## Optoelectronics

### Course Level

### Units

### Instructor(s)

### Prerequisite(s)

### Course Texts

Instructor will provide course notes.

### Course Description

**Specific Course Information:
2021-2022 Catalog Data: **Properties and applications of optoelectronic devices and systems. Topics include radiation sources, detectors and detector circuits, fiber optics, and electro-optical components.

### Learning Outcomes

**Specific Goals for the Course:
Outcomes of Instruction:** By the end of this course the student will be able to:

- Understand the electromagnetic spectrum, wave equation and wave propagation in linear, isotropic media and in anisotropic media.
- Understand basic radiometric quantities and perform analyses of basic radiometric designs.
- Utilize matrix methods to model and interpret image formation and beam propagation (both plane wave and Gaussian beam) in an optical system.
- Understand the function and design of an optical resonator.
- Calculate resonator mode characteristics and determine mode stability in an optical resonator
- Understand cavity Q, constructive and destructive interference.
- Interpret resonator output spectra including calculating and interpreting cavity finesse, resolution, mode spacing, etc.
- Understand the design and function of a Fabry-Perot etalon optical spectrum analyzer.
- Design an optical resonator (mirror curvature, size, separation, Gaussian beam characteristics in resonator) and understand sources of loss.
- Understand the function and design of laser gain media – gas, liquid, solid-state.
- Understand energy band diagrams, band gap, excited states, spontaneous emission, stimulated emission, state lifetimes, lineshape broadening: homogeneous and inhomogeneous, Einstein A and B coefficients, rate equations, exponential gain coefficient, population inversion, intensity.
- Design three and 4 level laser gain media based on desired design constraints.
- Understand the impact of placing the gain medium inside a resonator to produce a laser: laser gain profile, spectrum, threshold, population inversion, critical fluorescence power, stimulated emission power, output power.
- Understand the function and design of Q switch devices and methods and mode locking devices and methods.
- Discuss a variety of laser types (descriptions, pros, cons).

### Course Topics

**Brief list of topics to be covered:**

- Waves - electromagnetic, acoustic, traveling, standing. Electromagnetic spectrum. Review of basic terminology (homogeneous, linear, isotropic media, etc.) Maxwell’s equations and the wave equation.
- Polarization – linear, elliptical, circular, Jones vectors and matrices. Basic Radiometry.
- Image Formation – use of the refraction and translation (transfer) matrices to describe optical systems. Stability – beam path ray trace through an optical system to determine the stability of the system. Gaussian Beam Propagation – concepts and equations to determine the characteristics of a Gaussian beam. Imaging Gaussian Beams – combine the ABCD matrix method with Gaussian beams to propagate through an optical system.
- Resonator: mirrors separated by an air space. Propagation described by ABCD matrix with Gaussian beams.
- Cavity Q. Cavity modes, mode spacing, constructive and destructive interference Fabry-Perot etalon (optical spectrum analyzer), finesse, resolution.
- Resonator design (spherical mirrors), beam waist size and location in the cavity, confocal resonator properties, general resonator properties, matrix methods for resonator, resonator stability, sources of loss, output of resonator.
- Gain medium – gas, liquid, solid-state. Energy bands, band gap, ground state, excited states. Spontaneous emission, stimulated emission.
- Lineshape broadening: homogeneous and inhomogeneous.
- Einstein A and B coefficients, rate equations, exponential gain coefficient, population inversion, intensity.
- Three and 4 level lasers. Laser gain profile spectrum, impact of gain medium on resonator output. Gain medium inside the resonator. Threshold, population inversion.
- Critical fluorescence power, stimulated emission power, output power. Q switching and mode locking.
- Laser types (descriptions, pros, cons). Laser output: spectral, beam characteristics, etc.

### Relationship to Student Outcomes

ECE 456 contributes directly to the following specific electrical and computer engineering student outcomes of the ECE department:

1. An ability to identify, formulate, and solve complex engineering problems by applying principles of engineering, science, and mathematics.

3. An ability to communicate effectively with a range of audiences.

6. An ability to develop and conduct appropriate experimentation, analyze and interpret data, and use engineering judgment to draw conclusions.