Monolithic Master Oscillator Tilted Tapered Power Amplifier Emitting 9.5 W at 1060 nm

In this work, we present the design and performance of a monolithic master oscillator tilted tapered power amplifier emitting at 1060 nm. The device consists of three sections: a 2 mm long ridge waveguide (RW) master oscillator (MO) section with two surface distributed Bragg reflection (DBR) mirrors, a 0.5 mm long bent RW control (CON) section and a 3.5 mm long tapered power amplifier (TTPA) section tilted by 4°. With this design, unwanted back reflection from the front facet of the device towards the MO can be suppressed and the injection of the emitted light from the MO in the TTPA can be controlled by the applied current to the CON section. The device reaches an optical output power of up to 9.5 W. The emitted spectra are mode jump free over a wide power range having a spectrally narrow emission of Δλ <; 20 pm. By adjusting the control current an optimal driving condition of the device can be found with high output power, narrow spectral bandwidth and a nearly diffraction-limited beam quality factor (1/e ² ) M ² <; 1.5.