When a X-ray or g-irradiated alkali halide crystals (AHC) is exposed to 1060 nm infrared pulse of nanosecond duration from CO₂ laser, then shock waves produced in the crystals excites visible luminescence due to cleavage of the crystals. This is known as lasser-induced cleavage mechanoluminescence (ML). In the present investigation, NaCl, KCl, NaBr, KBr, and KI crystals are cleaved by laser and ML intensity is recorded. During cleavage, the ML intensity increases and attains a peak value at a particular time and then decays exponentially with time. The total ML intensity increases linearly with the area of the newly created surfaces. A theoretical approach has been proposed to explain the experimental results.