This free course, Digital communications, will illustrate how very high data rates can be transmitted over long distances through optical fibres. You will learn how these fibres are linked, examine the technology used and assess the future direction of this continually developing area of communication.

Learning outcomes:

• Convert between wavelengths and frequencies.
• Describe the main differences between lasers and LEDs as used as light sources for optical-fibre communications systems.
• Describe the difference between direct and external modulation of a laser.
• Describe the difference in structure and performance of step-index multimode, graded-index multimode and single-mode optical fibres.
• Draw up a power budget for an optical-fibre communication link and use it to estimate the maximum link distance.