of the sb and n can also be accomplished so that conduction band wells of at least 0 07 ev and valence band wells of at least 0 05 ev are achievable a preliminary description to fig1 11 will now be provided prior to describing the benefits of the invention in detail referring to fig1 portions of the illustrations in fig1 11 on the left hand side of the drawings are meant to graphically represent the position of a quantum well 11 barrier layers 12 and confinement layers 13 of a vcsel power is represented by drawing lines made vertically with respect to the position of the components mentioned on the right hand of fig1 11 strain for each illustrated device is also shown graphically with compression also being represented vertically downwards and tension represented vertically upwards referring to fig1 a graphical illustration of u201c energy v position u201d and u201c strain u201d for a vcsel having algaas confinement layers 13 gaas barrier layers 12 and an ingaas quantum well 11 is shown and will serve as a benchmark for adjustments made in fig2 11 with use of a ingaas quantum well on a gaas substrate longer wavelengths can be achieved however strain is also caused in the quantum well as shown by the depth 15 of the associated strain measurement referring to fig2 a vcsel is shown having algaas confinement layers gaas barrier layers and a ingaasn quantum well nitrogen is added to the ingaas quantum well of fig1 which resulted in a decrease 20 in energy and valence band confinement here in fig2 however strain was reduced 22 when compared to the nitrogen free device of fig1 referring to fig3 nitrogen n is also added to the barrier layers.