1971: FIBRE OPTICS - light's bright future? | Tomorrow's World | Retro Tech | BBC Archive

Summary

This script explores the advantages of fiber optics over traditional light bulbs, highlighting their safety, flexibility, and efficiency. Fiber optics, thin glass rods that transmit light without heat or electricity, are now more affordable due to mass production techniques. They are ideal for various applications, including medical procedures and traffic signs, where they offer precision, safety, and reliability. The script also touches on the aesthetic appeal of fiber optics.

Takeaways

• 💡 Light bulbs are hot, electrical, and vulnerable, unlike fiber optics which are cold to the touch and safe.
• 🌟 Fiber optics work by using a light source at one end of a thin glass rod, with light bouncing down the rod to emerge at the other end.
• 🔬 The production of fiber optics involves heating and fusing a central rod and an outer sheath, drawing them into a thin fiber, and winding them onto a drum.
• 📦 Fibers are assembled into bundles, bonded with epoxy, and enclosed in a tube for ease of handling.
• 💹 Advancements in production allow for the simultaneous drawing of 400 fibers, reducing costs by up to 20 times compared to previous methods.
• 🛠 Fiber optics can be bent and used in areas where traditional light sources are impractical or hazardous, such as inside the human body.
• 🦷 An example of fiber optics in medicine is attaching them to a dentist's drill to provide clear visibility without the risk of burning or electrical shock.
• 📋 Punch card readers traditionally use light bulbs to detect patterns of holes, but fiber optics provide a more reliable solution with a single light source and multiple tiny lights.
• 🚦 Fiber optics are used in traffic signs to avoid 'phantom images' caused by direct sunlight and to ensure fail-safe operation with backup lighting.
• 🚦 Fiber optic signs on motorways can carry bright light from a single lamp, saving costs and providing accurate, high-speed information.
• ✨ Fiber optics have aesthetic appeal in addition to their practical applications, as demonstrated in the script's closing remarks.

Q & A

What are the disadvantages of traditional light bulbs mentioned in the script?

Traditional light bulbs are hot, full of electricity, and very vulnerable.

What is a fiber optic and how does it work?

A fiber optic is a hair-thin coated glass rod that channels light from one end to the other by bouncing it back and forth down the rod. The light source can be placed at a distance, and the light itself is cold.

How are fiber optic rods produced?

Fiber optic rods are produced by heating the central rod and the outer sheath in a furnace until they fuse, then melting and drawing them off into a single thin fiber. As the fibers cool, they are wound onto a drum and assembled into bundles.

What is the significance of the mass production technique mentioned in the script?

The mass production technique allows for 400 fibers to be drawn off at the same time, which has significantly reduced production costs by as much as 20 times compared to the previous one-off production method.

How can fiber optics be applied economically due to the new production process?

The reduced costs due to the mass production technique enable fiber optics to be applied economically in many new ways, expanding their use to areas previously not feasible due to high costs.

What are the advantages of using fiber optics in medical applications, such as a dentist's drill?

Fiber optics can be used in medical applications like a dentist's drill to provide clear visibility without the risk of burning the patient's tongue or causing electrical shock, as they are cold to the touch and can be manipulated to reach specific areas.

How do punch card readers traditionally use light to identify information?

Traditional punch card readers use an array of miniature bulbs that shine light through the holes in the cards onto photocells, allowing the pattern of holes to be detected and information to be retrieved.

What is the fiber optic solution to the problem of bulb failure in punch card readers?

The fiber optic solution uses one light source and multiple tiny lights. If one light source fails, the system can still function because the light is distributed across many tiny lights, reducing the impact of a single bulb failure.

What is the issue with 'phantom images' on traffic signs and how do fiber optics address it?

Phantom images occur when direct sunlight illuminates unintended parts of a sign. Fiber optic signs avoid this issue because the tips of the fibers are too small to reflect enough sunlight to cause confusion, ensuring that the sign is only visible when intended.

How can fiber optics be made fail-safe for high-speed traffic signs?

Fiber optics can be made fail-safe by setting some fibers to monitor the light source and carry a sample light to a photosensitive cell. If the light goes out, the cell triggers a standby bulb in less than a second, ensuring continuous visibility for drivers.

What is the aesthetic appeal of fiber optics mentioned in the script?

Apart from their practical uses, fiber optics have a certain beauty of their own, as they can carry tremendously bright light in a controlled and visually appealing manner.