What Is the Difference Between Optics and Photonics?

Science has been studying light for centuries, but it’s only in the past few decades that optics and photonics became dedicated fields. Both photonics and optics design and engineering have given way to impactful innovations in medicine, defense, communications, entertainment, and more.

But what’s the difference between optics and photonics?

Optics and Photonics: The Study of Light

Optics and photonics share the study of the fundamental properties of light and harness them into practical applications. These two studies span the entire electromagnetic spectrum, from X-rays and gamma rays to ultraviolet, visible, and infrared light to radio waves.

Optics

Optics is a branch of physics that studies the behavior and properties of light, including how it interacts with matter and how instruments can use light or detect it.^[1] Typically, optics refers to the behavior of ultraviolet, visible, and infrared light, but light is an electromagnetic wave, and other forms of electromagnetic radiation, such as microwaves, exhibit similar properties.

• Classical optics, or geometrical optics, is concerned with manipulating light using devices such as lenses, mirrors, and prisms. This is often used in imaging lenses for cameras.
• Physical optics studies light as a wave rather than a particle, such as with holographic images.
• Quantum optics studies light phenomena where the particle, or quantum, nature of light is relevant. This is more for theoretical study than practical applications.

Optical science has relevance to multiple disciplines, including engineering, photography, medicine – particularly with optometry and ophthalmology – and astronomy. In practical applications, optics are used in mirrors, telescopes, lenses, lasers, microscopes, and fiber optics.

Photonics

Photonics is a branch of optics science that involves the generation, detection, and manipulation of light in the form of photons, or light particles.^[2] It may be done through emission, transmission, modulation, switching, amplification, signal processing, and sensing.

Light has a dual nature as a wave-particle duality. The light has characteristics of both a photon particle and an electromagnetic wave, but its nature depends on the interaction being observed.

Like optics, photonics typically includes the range of visible and near-infrared light, though it can span the whole electromagnetic spectrum.

Relationship Between Optics and Photonics

Photonics is closely related to optics. In modern optics, photonics is related to optomechanics, quantum mechanics, electro-optics, optoelectronics, and quantum electronics. In this field, photonics specifically connotes:

• The particle properties of light
• The potential of creating signal processing device technologies with photons
• The practical application of optics

Applications of Photonics and Optics

In practical application, photonics and optics are key to many ubiquitous advancements in society, ranging from mundane daily uses to advanced science. These include:

• Consumer Equipment: barcode scanners, remote control devices, printers
• Renewable energy: photovoltaics for solar power systems
• Telecommunications: optical fiber communications
• Industrial manufacturing: lasers for welding, cutting, and drilling
• Medicine: eye health, robotics, endoscopy, laser surgery
• Construction: laser rangefinding, smart structures
• Military: IR sensors, navigation, search and rescue
• Aviation: photonic gyroscopes
• Sensors: LIDAR, consumer electronics sensors
• Metrology: rangefinding, time, and frequency measurements
• Entertainment: holographic art, laser shows
• Security: anti-counterfeiting technology
• Photonic computing: communication between circuits and computers, quantum computing
• Biophotonics: medical diagnostics and environmental use

Optical Design at Apollo Optical Systems

At Apollo Optical Systems, our design is guided by the principle that the best design comes from an in-depth understanding of the problem and the physical principles that inform an effective solution. When you come to us for a custom optics project, we’ll work with you through every phase of the development cycle – design to prototyping to manufacturing – to ensure your project is set up for success. Contact us today to discuss your custom optics project!

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