The photon belt (photon ring, manasic ring, or golden nebula) is a fringe belief largely linked to some parts of the new age movement that a belt or ring of photons is going to, depending on the source of the information, fully envelope the Earth in 2012 and possibly cause massive failure of electrical equipment with 2-3 days of total darkness or total daylight, and/or initiate some kind of spiritual transition (usually referred to as "a shift in consciousness", "the shift of the ages", or just "the shift", with the time period leading up to the shift as "the quickening".)
It has also been referred to as "zero point" and ties in to various prophecies, the Mayan calendar, extraterrestrial life, etc...
Paranormal / Parapsychology
A Hubble Space Telescope image of the Pleiades
Terminology: Photon Belt
Definition: An astrological ring consisting of photons, said to intersect with the Earth's orbit in 2012.
Coined by: Paul Otto Hesse (1961) "Der Jüngste Tag"
AKA: Photon Ring, Manasic Ring, golden nebula
Status New Age belief
The core of the photon beltbeliefs is that an immense belt of photons exists, and orbits around the Pleiades (is a star cluster some 440 light years away from Earth, composed of some 500 stars.) According to some New Age beliefs, Earth will pass though this belt, resulting in either Humanity's elevation to a higher plain of existence or the end of the world.
Essene and Nidel write that it represents a temporary window for spiritual transition during which time humans can reach a higher point of existence. 
German scientist Paul Otto Hesse described his beliefs about the belt and its impact in his 1949 book Der Jüngste Tag (English: "The Recent Day").
The concept was further progressed in 1977 by Samael Aun Weor (Víctor Manuel Gómez Rodríguez), his lecture The Rings of Alcyone at the Conferencia Sobre Alcione ("Conference on Alcyone"), in which he cites mentions Hesse who predicts that if the Earth enters the belt first, a "great fire in the skies, or pyrotechnic lights" would occur"; but if the sun enters first,
"the radiation released would interfere with the solar rays and darkness would reign for 110 hours, after which everything would return to normal."
Weor refers to the photon belt as "Alcyone's rings" (or "the rings of Alcyone"). Alcyone, Weor claims, is the principle sun (star) of the Pleiades 7-star cluster.
According to Weor,
"It has been said that the sun which illuminates us is the seventh sun that circles Alcyone" and "Alcyone is, precisely, the principal sun of the Pleiades and in its orbit gravitate seven suns, our sun being the seventh which circles Alcyone".
Alcyone has rings made of "radiation" caused by the "splitting of the electron" which is released as energy by which Weor refers to as "manasic", a Sanskrit term for the mind that "is in some way related to the inferior manas (inferior mind), or to the superior manas (superior mind)" [of the subtle body].
The electrons, Weor purports, "release a type of unknown energy".
Thereabout, in the year of 1974, three astronauts who were circling the Earth reported a type of radiation, or a type of unknown energy, unsuspected by official science. Obviously, since 1962, specifically since the 4th of February of that year, our planet Earth, and in general, the whole solar system, has been on the verge of entering the terrible rings of Alcyone. ...
These rings extend for some light years; they are instantly enormous. Nevertheless, at any given moment, our solar system will enter Alcyone’s rings.
In August 1981, an Australian UFO magazine called Australian International UFO Flying Saucer Research Magazine #12 in an article called The Photon Belt Alcyone Saga by Shirley Kemp also mentions the photon belt (does not mention Rodriquez, but does mention Jose Comas Sola, Freidrich Wilhelm Bessel, Isaac Asimov, Edmund Halley, Paul Otto Hesse, and Erich Von Däniken).
It was reprinted in the Australian Nexus magazine in February 1991 as The Photon Belt Story, page 6.
On May 5 and June 23, 1992 the Phoenix Liberator mentions the photon belt. The photon belt is also mentioned in a few Phoenix Journals (years unknown but seems to be from the mid-1990s).
On June 8, 1992, the photon belt appears on Usenet in the newsgroup sci.astro.
In November 1992, in the channeled newsletter, Revelations of Awareness, the photon belt is mentioned in the section The Photon Belt: "Five Days of Darkness & No Electrical Power" Claims the Phoenix Liberator: This to Occur July 25, 1992. The newsletter refers to the photon belt in numerous issues thereafter.
In 1993, in Foster Perry's book, When Lightning Strikes a Hummingbird: The Awakening of a Healer, Barbara Hand Clow mentions the photon belt numerous times in the book's foreword.
In April 1994, the book You are Becoming a Galactic Human by Virginia Essene and Sheldan Nidel was published which mentions the photon belt:
1994: The photon belt, a huge toroid shaped object composed of photon light particles, was first discovered by your scientists in 1961 near the vicinity of the Pleiades by satellite instrumentation.
The book is an edited transcription of a series of messages channeled from Washta, a Sirian counselor and galactic presence, channeled through Nidel, who claims he has been receiving messages from the Sirians since he was nine.
In January 1998, Noel Huntley, Ph.D. wrote an article called The Photon-Belt Encounter which examines the origin and scientific credibility of the belt, which he refers to also as an "electromagnetic cloud".
Since 2000, the photon belt has been mentioned in other books such as The Pleidian Agenda by Barbara Hand Clow 
In the 2005 book Touched by the Dragon's Breath: Conversations at Colliding Rivers by Michael Harrington, the author mentions the photon belt numerous times and, in the foreword, refers to a 1987 meeting with John Redstone at "Colliding Rivers" who, the author claims, was familiar with the photon belt,
"a spectacular band of multi-dimensional light that St. Germaine had called the Golden Nebula" and "in esoteric circles it is known as the 'Dragon's Breath'."
Harrington also refers to,
"a Native American prophecy that told of a dynamic wave of energy traveling through space" and that "when the earth passed through this wave great changes would occur".
"This 'great transformation' would be preceded by a time of purification."
Criticism from Ufologists
In 1999, fringe physicist and ufologist Paul LaViolette, chairman of the Starbust Foundation, criticized assertions about the photon belt made by Shirley Kemp in a magazine published by the "Australian International UFO Research Society" (later reprinted in the February/March 1991 issue of Nexus).
He disputed Kemp's assertion that the belt had been detected by satellites in 1961, holding that no records of the such satellite findings was ever released, and that it was unlikely that equipment of the period would have been able to detect a belt such as was being described.
LaViolette also disputed Kemp's assertions about the movements of the belt and the solar system in relation to the star Alcyone, in the Pleiades cluster, saying that in order for Kemp's figures to be accurate the solar system would have to be traveling at 10% of the speed of light, while Alcyone itself would have to be approximately 1 billion times the mass of the sun in order to support such an orbit. 
A number of predictions have been made as to the date Earth's collision with the photon belt. So far, no observable effects attributable to the photon belt have been seen on those dates.
Dates so far given have included 1992 and 1997, a future date was given as 2011.
Mainstream science and the Photon Belt
While the concept of the Photon Belt is a New Age philosophy, some parts of the story can be analyzed scientifically. There is no scientific evidence for the existence of any sort of "photon belt".
A photon is the elementary particle that makes up light. To the extent that such a thing as a "photon belt" is physically possible, it would require the gravitational pull of a black hole, with light rays being bent around the black hole near the event horizon, forming a photon sphere.
Barring interaction with gravity or matter, photons otherwise always travel in straight lines.
(New Age) A huge, toroidal object composed of photons.
1993 — "According to many ancient Mayan esoteric beliefs, Alcyone is the central star of the Pleiadian star system, and our sun is the outermost star of this system. The Mayan Great Cycle is a calendar that delineates the [26,000]-year-long orbit of our sun and solar system around Alycone.
According to the latest discoveries in astronomy, our sun is moving into a "photon belt," or belt of light particles. As we move deeper and deeper into this photon belt, it would seem that we are moving into the Age of Light described in many ancient prophecies as well as by the Mayans.
My latest theory about the photon belt, which combines science, astrology, esoteric sources, and secret information given to me by indigenous people, is that we cyclically travel through this belt of light for  years and then travel outside of it for about [11,000] years."
2000 — "Having made this correlation, I am positive that the ancient Mayas truly knew about the Photon Belt. The fact that the solar system takes 24,000 years to revolve around the Pleiades, however, still has to be studied."
— Ohky Simine Forest,
Dreaming the Council Ways: True Native Teachings from the Red Lodge
2001 — "What happens as we approach the end of each cycle of 26,000 years is that our solar system enters a very high frequency area known as a Photon Belt. We first began to penetrate the Photon Belt in 1972, though we were only touching the edges."
2002-2004 — "The Photon Belt. For the most part, the Milky Way Galaxy is home to sentient, fully conscious beings with the exception of pockets of asleep, or partially-conscious beings, scattered here and there."