A novel method for real‐time measurement of ultrashort optical pulses generated from InGaAsP diode lasers at the wavelength of 1.3 &mgr;m has been realized by means of an ultrafast streak camera incorporating a frequency up‐conversion technique with a LiIO3crystal pumped by aQ‐switched neodymium: yttrium aluminum garnet (Nd:YAG) laser at 1.064 &mgr;m. The optical pulse from an InGaAsP double‐channel planar buried heterostructure (DC‐PBH) diode laser operated by a short pulse current of 1‐ns duration was measured to have a full width at half‐maximum (FWHM) of approximately 28 ps by single shot scanning with the temporal resolution of 8 ps. Using a 15‐mm‐long LiIO3crystal and 500‐W peak power of the pumping laser pulse focused at 400 &mgr;m in diameter, the up‐conversion efficiency and minimum detectable peak power of the diode laser pulse at 1.3 &mgr;m were estimated to be approximately 0.65% and 1 mW, respectively. This technique can be widely utilized for real‐time detection of ultrashort optical pulses in the wavelength range beyond 1–10 &mgr;m or more.