Kirkuk University Journal /Scientific Studies (KUJSS) Volume 14, Issue 2, June 2019 , pp. (53-71) ISSN: 1992-0849 (Print), 2616-6801 (Online) Web Site: www.uokirkuk.edu.iq/kujss E. mail: kujss@uokirkuk.edu.iq, kujss.journal@gmail.com 53 Theory of Mitigate Temperature Effect on the Equilibrium Point in Vertical Cavity Surface Emitting Lasers Hisham K. Hisham Department of Electrical Engineering, College of Engineering,University of Basrah, Basra, Iraq. husham_kadhum@yahoo.com Abstract This paper presents a way to mitigate the influence of temperature effects on the equilibrium point (Q-point) of vertical cavity surface emitting lasers (VCSELs) by investigating the effect of laser injection current (I inj ) and dc-bias level (I bias ) numerically using MATHCAD software. Results show that, by changing temperature 50 o C (i.e. from 10 to 60) with I inj = 3I th and I bias = 0, the photons density (P(t)) has decreased from 1.636 × 10 16 cm -3 to 0.733 × 10 16 cm -3 , the carrier density (N(t)) has increased from 2.367 × 10 18 cm -3 to 2.669 × 10 18 cm -3 and the laser output power (P out ) has decreased from the 2.366 mW to the 1.025 mW. In contrast, by increasing the I inj from 3I th to 5I th and the I bias from 0 to 1.5I th , the rate of the decreasing in the P(t) and in the P out have reduced more than 25%. Keywords: Equilibrium point, semiconductor lasers, vertical cavity surface emitting lasers, temperature effect. DOI: http://doi.org/10.32894/kujss.2019.14.2.4