Many applications of Laser diode require antireflection coatings either on one or both the facets of the diode. These include, for example, semiconductor optical amplifiers, optical pumping for solid state lasers and creation of broad... more
Many applications of Laser diode require antireflection coatings either on one or both the facets of the diode. These include, for example, semiconductor optical amplifiers, optical pumping for solid state lasers and creation of broad band source for tunable external cavity. We have used single layer antireflection coating on the front facet of the laser diode using electron beam evaporation technique to enhance optical power output from the facet. To optimize the coating conditions with precise control over facet reflectance of the laser diode, we have carried out experiment for In-Situ reflectivity measurement. We have used MgF2 as a low refractive index dielectric material for antireflection coating. The actual single layer AR coating consists of λ/4 thick MgF2 film. The reflectivity of the film being deposited is measured on GaAs test substrate, kept in close vicinity of the laser diode bar, with the help of a 657 nm (red) laser diode and a photo detector. A LabVIEW programme, called Virtual Instrument (VI), has been prepared to automate the whole experiment. We have also carried out simulation of facet reflectivity subject to the film thickness being deposited.
The power enhancement of laser diodes is achieved by single and multilayer facet coatings such as antireflection and high reflection respectively at the front facet and the back facet of the laser diode. In this work, we have experimented... more
The power enhancement of laser diodes is achieved by single and multilayer facet coatings such as antireflection and high reflection respectively at the front facet and the back facet of the laser diode. In this work, we have experimented with single layer λ/4 thick Al2O3 film for the Anti Reflection (AR) coating and stack of λ/4 thick Al2O3/ λ/4 thick Si bi-layers for the High Reflection (HR) coating. The AR/HR coatings were deposited in an electron beam evaporation system. The effect of front and back facet reflectivities on the output power of diode laser has been studied. The highly strained MOVPE grown InGaAs quantum-well edge emitting broad area (BA) diode lasers have been used for this experiments. The light output versus current (L-I) measurements were made on selected devices before and after the coatings. The devices were tested under pulsed operation with a pulse width of 400 ns and a duty cycle of 1:400. We have also carried out the theoretical analysis and simulation of L-I characteristics for this particular diode structure using LabVIEW. The experimental results were compared with simulated results. The effect of facet coating on external differential efficiency of diode laser has also been studied.
Many applications of Laser diode require antireflection coatings either on one or both the facets of the diode. These include, for example, semiconductor optical amplifiers, optical pumping for solid state lasers and creation of broad... more
Many applications of Laser diode require antireflection coatings either on one or both the facets of the diode. These include, for example, semiconductor optical amplifiers, optical pumping for solid state lasers and creation of broad band source for tunable external cavity. We have used single layer antireflection coating on the front facet of the laser diode using electron beam evaporation technique to enhance optical power output from the facet. To optimize the coating conditions with precise control over facet reflectance of the laser diode, we have carried out experiment for In-Situ reflectivity measurement. We have used MgF II as a low refractive index dielectric material for antireflection coating. The actual single layer AR coating consists of λ/4 thick MgF II film. The reflectivity of the film being deposited is measured on GaAs test substrate, kept in close vicinity of the laser diode bar, with the help of a 657 nm (red) laser diode and a photo detector. A LabVIEW programme, called Virtual Instrument (VI), has been prepared to automate the whole experiment. We have also carried out simulation of facet reflectivity subject to the film thickness being deposited.
Many applications of Laser diode require antireflection coatings either on one or both the facets of the diode. These include, for example, semiconductor optical amplifiers, optical pumping for solid state lasers and creation of broad... more
Many applications of Laser diode require antireflection coatings either on one or both the facets of the diode. These include, for example, semiconductor optical amplifiers, optical pumping for solid state lasers and creation of broad band source for tunable external cavity. We have used single layer antireflection coating on the front facet of the laser diode using electron beam evaporation technique to enhance optical power output from the facet. To optimize the coating conditions with precise control over facet reflectance of the laser diode, we have carried out experiment for In-Situ reflectivity measurement. We have used MgF2 as a low refractive index dielectric material for antireflection coating. The actual single layer AR coating consists of λ/4 thick MgF2 film. The reflectivity of the film being deposited is measured on GaAs test substrate, kept in close vicinity of the laser diode bar, with the help of a 657 nm (red) laser diode and a photo detector. A LabVIEW programme, called Virtual Instrument (VI), has been prepared to automate the whole experiment. We have also carried out simulation of facet reflectivity subject to the film thickness being deposited.
The power enhancement of laser diodes is achieved by single and multilayer facet coatings such as antireflection and high reflection respectively at the front facet and the back facet of the laser diode. In this work, we have experimented... more
The power enhancement of laser diodes is achieved by single and multilayer facet coatings such as antireflection and high reflection respectively at the front facet and the back facet of the laser diode. In this work, we have experimented with single layer λ/4 thick Al IIO 3 film for the Anti Reflection (AR) coating and stack of λ/4 thick Al IIO 3/ λ/4 thick Si bi-layers for the High Reflection (HR) coating. The AR/HR coatings were deposited in an electron beam evaporation system. The effect of front and back facet reflectivities on the output power of diode laser has been studied. The highly strained MOVPE grown InGaAs quantum-well edge emitting broad area (BA) diode lasers have been used for this experiments. The light output versus current (L-I) measurements were made on selected devices before and after the coatings. The devices were tested under pulsed operation with a pulse width of 400 ns and a duty cycle of 1:400. We have also carried out the theoretical analysis and simulation of L-I characteristics for this particular diode structure using LabVIEW. The experimental results were compared with simulated results. The effect of facet coating on external differential efficiency of diode laser has also been studied.
The power enhancement of laser diodes is achieved by single and multilayer facet coatings such as antireflection and high reflection respectively at the front facet and the back facet of the laser diode. In this work, we have experimented... more
The power enhancement of laser diodes is achieved by single and multilayer facet coatings such as antireflection and high reflection respectively at the front facet and the back facet of the laser diode. In this work, we have experimented with single layer λ/4 thick Al2O3 film for the Anti Reflection (AR) coating and stack of λ/4 thick Al2O3/ λ/4 thick Si bi-layers for the High Reflection (HR) coating. The AR/HR coatings were deposited in an electron beam evaporation system. The effect of front and back facet reflectivities on the output power of diode laser has been studied. The highly strained MOVPE grown InGaAs quantum-well edge emitting broad area (BA) diode lasers have been used for this experiments. The light output versus current (L-I) measurements were made on selected devices before and after the coatings. The devices were tested under pulsed operation with a pulse width of 400 ns and a duty cycle of 1:400. We have also carried out the theoretical analysis and simulation of L-I characteristics for this particular diode structure using LabVIEW. The experimental results were compared with simulated results. The effect of facet coating on external differential efficiency of diode laser has also been studied.
