Blue laser diode
The blue laser diode is an electronic device that produces blue color laser beam, we know at the electromagnetic color spectrum red color has the highest and blue color had the lowest wavelength, conventionally red color laser is available the most, this is because they invented first and it had lower cost.
But the blue color lays at the shorter wavelength region, a proper blue color laser beam production is always a difficult task, but here we explain the blue laser diode construction and important details.
Construction of blue laser diode
The construction of all the laser diodes is the same, the figure above indicates the internal arrangement for a laser diode.
Generally, laser diodes are been constructed with multiple semiconductor materials.
The laser diode construction is much similar to the construction of pin diode because a shorter-sized intermediate layer is sandwiched between two larger layers.
And the intermediate is made with glass material to provide support at the operation of the laser diode.
This figure shows the internal arrangement of a blue laser diode, the wavelength range of the blue beam is between 450nm to 480nm.
Normally solid-state or semiconductor blue laser diode device is normally constructed with gallium nitride GaN or indium gallium nitride.
As we can see n-type is built with GaAs, GaInP (substrate stop layer), n- with AIInP, and n+ are with GaAs substrate.
And P-type is built with P is GaAs and P- is AIInp.
Generally, the laser diode construction is heterogenic, multiple layers are arranged like a sandwich.
Working of blue laser diode
The figure shows the working operation of the blue laser diode, the whole working of the laser diode is been divided into three stimulated absorption, spontaneous emission, and stimulated emission.
At the operation, when the electrical energy strikes the material, the electrons are ejected from the hole to another energy level, this operation is called the stimulated absorption.
Then after the electron reaches a different energy level, it remains there for few nanoseconds, and coming back to the hole, the recombination of hole and electrons will produce energy called a photon, this phenomenon is called the spontaneous emission.
The produced photon remains in the laser housing, with the help of glass, and then the photon strikes into another electron at the higher energy level and the recombination of electron and hole happened again and release another photon, this process is called the stimulated emission.
Both the photons produced are coherent to each other because the wavelength of both waves is in phase in space and time, this is how the laser beams are produced.
At the operation of blue laser diode, we need to consider two types of lasers with two different operations such as frequency doubling and diode-pumped solid-state.
Blue light beam production
The material used to build the blue laser diode is the gallium nitride GaN or indium gallium nitride, the light beam produced is blue or violet, the wavelength of blue is very close to violet, which is why we see it as blue.
The blue light radiation is produced by helium-cadmium gases lasers and argon-ion.
Applications of blue laser diode
- Telecommunication systems
- Laser printer systems
- Digital photofinishing
- Data recording
- Laser microscopy
- Protection displays
- Spectroscopic measurements
- Eco monitoring systems
- Medical applications
- DVD players
- Cutting tool
- 3D projectors