What I Wish Everyone Knew About Laser Diodes

Let’s look at the past and see the history of laser diodes. The answer lies in the past pages from Albert Einstein, who in 1917 primarily defined the code of stimulated emission. It states that an energetic electron or molecule can give energy via a ray. Ideally, this emission is provoked by giving power to a light-amplifying element (the laser-active element or medium), thus getting it to an intense power level (an excited state). 

This energy store is called “pumping” in terms of laser technology. The formerly absorbed energy is the ray of light when the excited electrons or molecules fall back into their formal state. Let’s define a laser diode and also know about its different types.

What I Wish Everyone Knew About Laser Diode

What is a Laser Diode?

The laser diode technology is similar to LED as semiconductors deliver coherent waves. These waves have the same frequency and motion on an infrared medium. And as they use p-n junctions to produce waves, they are also known as injection laser diodes

Now that we know what a Laser Diode is, let’s look at its various types. 

Types of Laser Diodes

There are mainly four types of Laser Diodes, namely, 

Double Heterostructure Laser Diode: 

In this laser diode, a heterostructure is formed by placing layers of low bandgap material on either side of high bandgap layers, hence known as a double heterostructure laser diode. In this type, the heterostructure is stuffed between the p-type and the n-type. They are mainly used for optical amplification as they activate a particular area. 

Quantum Well Laser Diode: 

These diodes are responsible for improved efficiency. Let’s understand how. There is a thin layer of the quantum well in the middle of the diode, this layer converts the electrons from high energy to lower energy, and thus it results in improved efficiency of a gadget. 

Separate Confinement Heterostructure Laser Diode:

Light emission is improved in separate confinement heterostructure diodes. This laser diode has three layers to balance the light emission which solves the light-limiting effect problems of other laser diodes.

Vertical-Cavity Surface-Emitting laser diode:

As the name suggests, vertical-cavity; in this type of laser diode, the optical cavity is placed parallel to the current flow. Thus, the partially reflecting mirrors are put near the extremities of the optical cavity.

Now that we know the four main kinds of laser diodes, let’s have a look at the characteristics of these diodes. 

Characteristics of Laser Diodes 

There are three main characteristics of a laser diode. They are as follows: 


The foremost characteristic is coherence. That is, the wavelengths of the laser light are consistent and in proper wide length. 


The second characteristic is monochromaticity, which implies that the colour of the light is a single colour. They cannot have multiple colours all at once; thus, being monochromatic is one characteristic of a laser diode. 

Brightness & Directionality

The last characteristic is brightness and directionality. Laser light is emitted narrowly and, thus, has a direction, unlike other light sources, such as a bulb or candle, which emits light in multiple directions. And as the light emitted is narrow, they are sharp and bright. 

These are the top three characteristics of a laser diode; now, let’s briefly look at its advantages and disadvantages. 

Advantages Of A Laser Diode

Disadvantages Of A Laser Diode

Applications Of Laser Diodes

Electronic Devices: These laser diodes are widely used in electronic gadgets such as DVS, CDS and Printers. 

Industries: The high-power laser diodes are mainly used for cutting, drilling and welding. The high-intensity laser beam generated by laser diodes makes cutting heavy materials more accessible. 

Medical Equipment: In the medical field, it is used for non-invasive treatments, such as removing unwanted tissues & tumours and also in dental treatments. 

We have come to the end of this blog, and we hope you gained some insights about laser diodes. And still, if you have any queries, then we’ll answer them as soon as possible.

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