Masao Imaki

High-Power 1.06-

We designed a 1.06-mum single-quantum-well (SQW) InGaAs/AlGaAs planar tapered amplifier that was injected with seed light of a fiber Bragg grating stabilized laser diode through a fiber biconical microlens. To increase the amplifier output, the microlens with approximately 3- and 11-mum radii on vertical and horizontal axes, respectively, provides high coupling efficiency between the laser diode and the amplifier. The microlens also controls propagation in the tapered gain area to suppress the filament formation. In addition, the small radii of the microlens reduce near-end reflection at the amplifier input to prevent parasitic laser oscillation of the amplifier. We demonstrated near-diffraction-limited output of 5.5 W with the beam quality factor M2 of 1.5 by using a 3-mm-long amplifier having an optical confinement factor of 1.2%.

\mu{\hbox {m}}

We demonstrated a compact linear-polarized planer waveguide laser with diode proximity-coupling pump geometry, and uniaxial laser material of Nd:GdVO4 The laser cavity size is as small as 4-mm times 1 mm including the 5-stripe pumping diode, the total output power of 1.7-W for five independent nearly diffraction- limited beams was obtained at the pumping diode output power of 5.7-W.

Near-Diffraction-Limited Planar Tapered Amplifier Injected With Seed Light Through a Fiber Biconical Microlens

We have newly devised an athermal birefringent solid etalon for a built-in 25 GHz spacing DWDM wavelength monitor, which has a thermal property as low as 0 pm//spl deg/C. This monitor integrated DFB-LD module is confirmed to have a high stability.