Abstract: A laser diode includes an n-type semiconductor region, a p-type semiconductor region, a semiconductor mesa provided between the n-type semiconductor region and the p-type semiconductor region, the semiconductor mesa including an active layer, and a semiconductor burying region located between the n-type semiconductor region and the p-type semiconductor region, the semiconductor burying region being provided on a side face of the semiconductor mesa. The semiconductor burying region includes an n-type semiconductor burying layer and a p-type semiconductor burying layer. The n-type semiconductor burying layer is provided between the p-type semiconductor region and the p-type semiconductor burying layer. The p-type semiconductor burying layer is doped with an element that forms an electron trapping level in the band gap of the p-type semiconductor burying layer.

Abstract: A laser diode includes an n-type semiconductor region, a p-type semiconductor region, a semiconductor mesa provided between the n-type semiconductor region and the p-type semiconductor region, the semiconductor mesa including an active layer, and a semiconductor burying region located between the n-type semiconductor region and the p-type semiconductor region, the semiconductor burying region being provided on a side face of the semiconductor mesa. The semiconductor burying region includes an n-type semiconductor burying layer and a p-type semiconductor burying layer. The n-type semiconductor burying layer is provided between the p-type semiconductor region and the p-type semiconductor burying layer. The p-type semiconductor burying layer is doped with an element that forms an electron trapping level in the band gap of the p-type semiconductor burying layer.

Abstract: The present application provides a laser diode that enables to reduce the differential resistance. The laser diode of the invention provides first and second guiding layer in an n-side of an active layer. The first guiding layer is put between the active layer and the n-type cladding layer; while, the second guiding layer is put between the first cladding layer and the active layer. These first and second guiding layers are intrinsic layers or p-type layers, where the conduction band level of the second guiding layer is lower than that of the first guiding layer, while the band gap wavelength of the first guiding layer is shorter than that of the second guiding layer.

Abstract: The present application provides a laser diode that enables to reduce the differential resistance. The laser diode of the invention provides first and second guiding layer in an n-side of an active layer. The first guiding layer is put between the active layer and the n-type cladding layer; while, the second guiding layer is put between the first cladding layer and the active layer. These first and second guiding layers are intrinsic layers or p-type layers, where the conduction band level of the second guiding layer is lower than that of the first guiding layer, while the band gap wavelength of the first guiding layer is shorter than that of the second guiding layer.

Abstract: A package contains therein a semiconductor laser element for emitting light and a semiconductor circuit element for driving the semiconductor laser element and is provided with an optical fiber supporting face and a back face. The optical fiber supporting face is provided for supporting an optical fiber for transmitting the light from the semiconductor laser element, and the back face is opposed to the optical fiber supporting face. The back face has a lead pin for feeding a positive-phase signal into the semiconductor circuit element and a lead pin for feeding a negative-phase signal into the semiconductor circuit element. The lead pins penetrate through the back face. The semiconductor circuit element receives positive-phase and complementary negative-phase signals, both including a high-frequency component of 10 GHz or higher, through the lead pins, converts these signals into a single-ended signal, and outputs the resulting signal to the semiconductor laser element.

Abstract: A package 22 contains therein a semiconductor laser element 12 for emitting light and a semiconductor circuit element 14 for driving the semiconductor laser element 12 and is provided with an optical fiber supporting face 44 and an back face 46. The optical fiber supporting face 44 is provided for supporting an optical fiber 16 for transmitting the light from the semiconductor laser element 12, and the back face 46 is opposed to the optical fiber supporting face 44. The back face 46 has a lead pin 31 for feeding a positive-phase signal into the semiconductor circuit element 14 and a lead pin 32 for feeding a negative-phase signal into the semiconductor circuit element. The lead pins 31 and 32 penetrate through the back face 46.