Jan Opschoor

Diffraction-limited circular single spot from phased array lasers

Anamorphic prism optics makes it possible to obtain a diffraction-limited (lambda/8) circular single spot from index guided phased array lasers. It served not only for beam shaping but also for astigmatism correction and spatial filtering. The optical path analysis based on the interferometric fringe scanning phase measurements both in the near and far fields indicates that the phased array lasers can be applied to such diffraction-limited precise optical systems as optical disk recording, laser beam printing, or second harmonics generation.

Visible Y‐junction diode laser with mixed coupling

An experimental study and theoretical analysis of a phase‐locked, visible, λ=670 nm, 2‐3 Y‐junction semiconductor laser array are presented. In a ridgetype 2‐3 Y‐junction, AlInGaP/InGaP array, both in‐phase and anti‐phase array modes are observed to lase simultaneously. The experimental results are discussed in the framework of a model based on the beam propagation method. The influence of the presence of both interferometric and evanescent coupling on the array modes is analyzed.

Power saturation in 2-1 Y-junction diode lasers

An experimental and theoretical study of 2-1 Y-junction semiconductor lasers is presented. In a V-channeled substrate inner stripe laser (VSIS)-type antireflection coated 2-1 Y-junction array lasing at a wavelength of 780 nm, stable in-phase operation is observed up to a CW output power of 100 mW. In uncoated devices, saturation effects occur which limit stable in-phase operation to low-power output. The experimental results are discussed in the framework of a model based on the beam propagation method. >