Lestari, G.MinarniSaktioto2013-07-132013-07-132013-07-13Rangga Dwijunanda Putrahttp://repository.unri.ac.id:80/handle/123456789/4283Diode laser is a laser with a semiconductor material. Nowdays, it is available at a relatively low price in different wavelength. The wavelength can be measured using the diffraction method with diffraction grating. In this research there are two types of diffraction grating i.e a reflection grating using a compact disc (CD) and a transmission grating from Phywee with 300 slits/mm. They were used for measuring the wavelength of four diode lasers with different wavelengths. The CD used are two empty CDs with the capacity of 720 MB and 700 MB, respectively. In order to be used as a reflection grating, the distance between pits in the CD must be known as a slit width. The distance was measured using a He-Ne laser light with a stable wavelength of 632,8 nm. The research results showed that the distance between pit width obtained are 1463,6  6,2 nm and 1454,4  4,1 nm for each CD. The measurement using the transmission grating has a lower standard deviation than the measurement using the reflection grating i.e 532,0  0,7 nm and 532,4  1,8 nm; 633,4  1,67 nm and 637,8  3,1 nm; 834,1  3,1nm and 835,3  5,1 nm, in contrast with an infrared laser (Near IR) with standard deviations lower for the reflection grating which are 786,7  1,7 nm and 784,4  2,5 nm. These values are comparable to the values listed on the packaging of each Laser which are Green Laser 532 nm, Red 638 nm, Infrared (Near IR) 785 nm and Infrared 830 nm.otherWavelengthCompact DiscDiffraction GratingHe-Ne LaserDiode laserOther