Optical Transmitter Experiment Report

This report details the study of fiber optic transmitters, their components, and signal transmission characteristics over varying fiber lengths. 1.

Objectives

To study the structures and characteristics of light sources used in fiber optic transmitters, such as LEDs and laser diodes. To examine the components of a fiber optic communication system, including the transmitter, optical fiber, and receiver. To observe energy loss in optical fibers at different transmission distances and analyze its effect on signal integrity.

2.

Equipment and Materials

Function Generator (for analog and digital signals)Optical Fiber Cables: 1-meter, 5-meter, and 10-meter duplex fibersFiber Optic Transmitter Module (e.g., KL-95001)Oscilloscope (2-channel)AC-to-DC Power AdapterConnecting Leads and JumpersReceiver Module with comparator and low-pass filter 3.

Experimental Procedure

Place the transmitter module on the worktable and ensure the data transceiver mode selector is in the OFF position. Connect the function generator output to the transmitter input and the oscilloscope channel 1 input using connecting leads. Connect the receiver output to a speaker or measurement device using a jumper cable.

Transmit signals through optical fibers of varying lengths (1 m, 5 m, 10 m) and record the received signal voltages on the oscilloscope. Adjust the transmitter bias and modulator settings to ensure proper signal amplitude and waveform integrity. Measure rise and fall times of the transmitted signal to evaluate the response of the optical transmitter.

4.

Data and Results

Fiber Length

Received Voltage (V)1 meter5. 605 meters5. 4610 meters5.

23The data shows a gradual decrease in voltage with increasing fiber length, indicating energy loss proportional to transmission distance. 5.

Observations

Signal amplitude decreases slightly as fiber length increases, demonstrating attenuation in the optical fiber. The 5-meter duplex fiber successfully transmitted audio signals with minimal distortion, confirming reliable short-distance transmission. Rise and fall times of the transmitted signal were consistent with the expected response of the laser diode and driver circuit.

6.

Conclusion

The experiment successfully met its objectives by analyzing the structure and function of fiber optic transmitters, studying system components, and observing energy loss over different fiber lengths. The results highlight the importance of fiber length on signal integrity and demonstrate the reliable transmission of electrical signals converted to optical form. These findings provide practical insights into the operational dynamics and performance characteristics of fiber optic communication systems.

7.

References

Optical Communication Lab Manual, Studylib.net Experiment No. 6 Optical Fiber Driver (Transmitter), University of Technology LOFRANCO & SARIGUMBA, Fiber Optic Transmitter Experiment Report