LEOK-40 is a comprehensive experiment kit designed to cover a wide range of experiments in modern optics, such as applied optics, information optics, physical optics, and holography. Composed of multiple optical components, adjustable holders, and light sources, this kit can be configured flexibly for conducting various experiments in modern optics. Through selecting and assembling the corresponding components into setups, students can get a better understanding of modern optics, and enhance their experimental skills and problem solving ability. The following experiment examples can be conducted using this kit: 1.Measure lens focal length using auto-collimation method 2.Measure lens focal length using displacement method 3.Measure air refractive index by building a Michelson interferometer 4.Measure the nodal locations and focal length of a lens-group 5.Assemble a telescope and measure its magnification 6.Observe the six types of aberrations of a lens 7.Construct a Mach-Zehnder interferometer 8.Construct a Sagnac interferometer 9.Measure the wavelength separation of Sodium D-lines using a Fabry-Perot interferometer 10.Construct a prism spectrographic system 11.Record and reconstruct holograms 12.Record a holographic grating 13.Abbe imaging and optical spatial filtering 14.Pseudo-color encoding 15.Measure grating constant 16.Optical image addition and subtraction 17.Optical image differentiation 18.Fraunhofer diffraction