2023.ph.876.1: A long (~2 m) glass assembly consisting mainly of a narrow tube with three larger cylindrical bulbs attached at intervals along its length. The bulbs have metal elements mounted at their centre. These are joined to a metal wire emerging from the glass envelope. The larger of the three bulbs has a glass stem protruding from it. This is coated in places with a wax-like material. This is presumably a connection point used for refilling. The narrow tube has slanted optical elements at either end.
This glass element is mounted on a temporary platform made of pine lumber with supports of FDM-printed PLA plastic. This was made in September of 2023 when the tubes were acquired in order to provide a stable support for storing the tube.
Note that this tube was originally stored on an aluminum platform that was not acquired due to its size. However, the following mounting and optical elements were acquired from that platform:
2023.ph.876.2-4: Three aluminum supports with micrometer adjustments for adjusting the vertical alignment of the narrow tube.
2023.ph.876.5-6: Two aluminum elements, labelled “Front” and “Back” respectively, each housing a partially reflecting mirror. Two micrometer screws on each element adjust the mirror along the vertical and horizontal axes.
2023.ph.876.7: A collection of fasteners and mounting hardware: Eight hex nut screws and two washers used to secure the above elements from the aluminum base from which they were removed. One aluminum plate with two holes.
Accession Number: 2023.ph.876.1-6
Alternative Name:
Primary Materials: Glass, Aluminum
Markings:
Glass Tube: Height = 26, Width = 20, Length = 192.
A helium neon (He-Ne) laser is a form of gas laser. It operates using a mixture of helium and neon excited by a high voltage electrical discharge. This example operates at the 632.8 nm wavelength.
He-Ne lasers were once a popular demonstration apparatus because they are relatively simple to operate compared to other lasers of comparable power operating in the visible spectrum. They have been largely replaced in this role by semiconductor lasers. This example is unusually long. More recent He-Ne lasers are typically much shorter (~.3m) due to improvements in mirrors and electronics.
This item is in good cosmetic condition and has no obvious damage. The aluminum platform to which it was attached was not retained due to its size. However, the mounting/ alignment pieces and the end mirrors were collected.
Associated Instruments:
Manufacturer: University of Toronto
Date of Manufacture: 1960s
This artifact was acquired from the Department of Physics teaching lab, along with a second, similar, laser tube (2023.ph.877), on July 26, 2023.
This laser and 2023.ph.876.7 were designed by Professor of Physics A. David May who was a professor at the University of Toronto from 1961 until the mid-1990s.
The lasers were likely made in the period 1963-1966, with assistance from a glassblower, likely Jack Legge. The lasers were likely used for demonstration purposes, and were eventually acquired by the Department of Physics advanced undergraduate lab. There they were used to demonstrate different types of transverse modes, and the temporal frequency difference between such modes.
Details about this artifact’s provenance were obtained through email correspondence with Professor Emeritus Henry van Driel on October 2, 2023.
Historical Notes:
- Donated to UTSIC