Modal noise reduction of laser diodes with specific thickness coating

A low facet reflectivity laser diode is able to oscillate in multilongitudinal modes, and has a high relative intensity noise (RIN) and reduces mode hopping noise. By introducing the electron-cyclotron-resonance (ECR) plasma deposition method, a good facet coating film has been obtained. We have demonstrated that a specific coated laser has very low modal noise characteristics even under direct analogue intensity modulation.