Differences between DBR & DFB Lasers
DBR and
DFB lasers are the two most familiar and most used lasers with high power
single frequency. Both of these lasers have distinct applications in various
industries. The high efficiency and exceptional spectral purity enable them to
be used in multiple scientific instruments.
This article discussed everything about laser diodes- from the definition, types to
characteristics. Further, we have also explained the difference between DRB and
DFB lasers in the later section. Let us begin with what is a laser diode.
What
is Laser Diode?
A laser
diode can be defined as the semiconductor device that generates high-intensity
coherent light by converting electrical current into light, where, the word
LASER stands for Light Amplification by Stimulated Emission of Radiation.
All of
the lasers, including the DFB laser, generate a very sharp and narrow beam of
light, which is used in many technologies and industries such as laser
printers, DNA sequencing instruments, laser surgery, optical communication, and
skin treatment, among others.
Types
of Laser Diodes
We can
classify the laser diodes into four principally different types, namely,
- Double
heterostructure laser diodes
- Quantum
well laser diode
- Separate
confinement heterostructure laser diodes, and
- Vertical
cavity surface-emitting laser diode
Along with these, there are many other sub-types of laser diodes too. Such as,
5. Distributed Feedback Laser Diode- also known as DFB laser
- Distributed
Bragg Reflector Laser Diode also is known as DBR laser
- Quantum
Cascade Laser Diode
- External
Cavity Diode Laser
- Vertical External Cavity Surface Emitting Laser Diode (VCSEL), and
- Interband Cascade Laser Diode
It is to
be noted that each of these lasers is used based on its characteristics, and it
has different applications. For example, DFB lasers are used in communication
and clinical applications because of its smooth control of wavelength and
narrow spectral width. At the same time, VCSEL is used in various laser-based
products such as face ID, laser printers, smart glasses, and biomedical
sensing.
Characteristics
of Laser Diodes
Almost
all the laser diodes, including DFB laser and VCSE laser, have the following
five characteristics.
- Directionality: The
laser beam emits highly directional light, having almost zero laser
divergence.
- Monochromaticity: The laser light is nearly monochromatic in nature.
- Coherence: Laser is highly coherent. Indeed, it is the main characteristic of the laser that distinguishes it from other light sources.
- Intensity: Compared to other light sources, laser beams are highly intense. Its power is concentrated in a tiny diameter beam.
- Brightness: Due to the continuous reflections, laser light produces a beam of high intensity as well as brightness.
DFB
Laser Vs DBR Laser
Although
there are many similarities between DRB and DFB lasers, there are many
differences too. Such as,
Both of
these lasers have a different grating location. The DRB uses high reflectivity
surface grating, whereas the DFB laser uses low reflectivity surface grating.
Another significant difference between these two lasers is the mode of
selection. DFB lasers operate with two modes while DBR laser operates only at
the single longitudinal mode.
We hope
these points and information have cleared all your doubts and confusion related
to the laser diode. These details may have also helped you to clarify how DBR
and DFB lasers are different.
At Inphenix, we develop and deliver an extensive
range of DFB lasers. All of its lasers have a simple implementation and
low-cost fabrication process. Along with lasers, we also offer a broad range of
other light sources such as VCLELs, swept source laser, superluminescent diode
devices, etc. Check out our official website to get more information about our
products and services.
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