[填空题]
Light of wavelength 590 yhg95zl lr 5lx;-gg e6ya5pa45k.ec1m* ;nm7 3.ioqascuqqsnm passes through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mmiqo3smqm7;eq51 n ca*.s. cuk closer to the central maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$ nm
