A Directly Modulated (DML) laser diode chip is a type of laser diode chip that can be directly modulated by varying the current injected into the laser diode. The modulation of the current causes a corresponding modulation of the intensity of the light emitted from the laser diode.
DML laser diode chips are widely used in applications where cost-effectiveness and simplicity are key requirements, such as in short-range optical communication systems, such as local area networks (LANs) and passive optical networks (PONs). They are also used in some sensing applications.
Compared to EML laser diode chips, DML laser diode chips offer a lower modulation speed, higher chirp, and higher drive voltage. However, they are more cost-effective and require less power to operate.
To improve the performance of DML laser diode chips, various techniques such as impedance matching and temperature stabilization can be used to reduce the drive voltage and increase the modulation bandwidth. Additionally, external cavity techniques such as distributed Bragg reflectors (DBRs) can be used to further stabilize the emission wavelength and enhance the output power.
Directly modulated laser or DML chip is a type of DFB laser diode chip with a higher data rate than FP LDs. DMLs are used in fiberoptic communication, and their performance degrades over distance compared to EML.