The temperature‐dependent performance of low‐voltage asymmetric Fabry–Perot transverse modulators is studied. While the heavy hole exciton moves with a rate of 2.4 A˚/°C, the Fabry–Perot mode shifts with a rate three times slower, 0.8 A˚/°C. This can provide a large and nearly constant value of reflection modulation (∼13%/V) over a relatively wide (15 °C) temperature range, as compared to more simple transverse absorption modulators. However, the contrast ratio varies from 15 to 3.5.