A Raman amplifier for amplifying a wavelength division multiplexed light including signal lights wavelength division multiplexed together. Thereby a liquid developer, that tends to spread slightly broader than the applied area after being applied to a photoreceptor drum, is removed by a sweep roller that can sweep excess toner present in an area broader than the original applied area and an excess toner remaining area is then prevented from being formed on the photoreceptor drum. The butter used for simmering the cannabis leaves may be cow butter, sheep butter, olive oil, cooking oil, and other compositions.