Excitation of high-radial-order Laguerre-Gaussian modes in a solid-state laser using a lower-loss digitally controlled amplitude mask

• Published in: Journal of optics (2010) Vol. 19; no. 10; pp. 105604 - 105611
• Main Authors: Bell, T, Hasnaoui, A, Ait-Ameur, K, Ngcobo, S
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.10.2017
• Subjects: laser beam characterization; laser resonators; solid-state lasers; spatial light modulators
• ISSN: 2040-8978; 2040-8986
• DOI: 10.1088/2040-8986/aa81f9

In this paper we experimentally demonstrate selective excitation of high-radial-order Laguerre-Gaussian (LGp or LG p , 0 ) modes with radial order p = 1-4 and azimuthal order l = 0 using a diode-pump solid-state laser (DPSSL) that is digitally controlled by a spatial light modulator (SLM). We encoded an amplitude mask containing p-absorbing rings, of various incompleteness (segmented) on grey-scale computer-generated digital holograms, and displayed them on an SLM which acted as an end mirror of the diode-pumped solid-state digital laser. The various incomplete ( ) p-absorbing rings were digitally encoded to match the zero-intensity nulls of the desired LGp mode. We show that the creation of LGp, for p = 1 to p = 4, only requires an incomplete circular p-absorbing ring that has a completeness of 37.5%, giving the DPSSL resonator a lower pump threshold power while maintaining the same laser characteristics (such as beam propagation properties).