This interference pattern can be produced by anyone in less than a minute using a laser pointer and index cards from their desk drawer ( it also works with a tuned laser and metal barriers ). However, understanding the results is not as easy.

First let me review some nonanomalous results. Two barriers placed 4mm apart will of course produce a symmetrical single slit interference pattern. If one barrier, say the left barrier, is moved further ahead then the pattern becomes asymmetrical with large bans and spacing on the left and fine bans and spacing on the right.

This is of course the pattern when the angle of incidence between the laser and the slit becomes acute. The difference becomes even greater if the barrier edges are moved further into the laser path or if the left barrier is moved even further ahead; making the the angle between the laser path and the line between the edges more acute. Eventually the left ban will become a solid streak and the right bans will be extremely fine.

So far every thing is according to existing theory. The fun starts when the barrier edges are cut on a five degree slope to create a "v" like slit. The first beveled barrier is placed on the right at 2mm from the center of the laser path and at least 3m from the laser ( this distance is required to create a pattern comparison later ); and, the second beveled barrier is placed on the left at 2mm from the center of the laser path at an additional 40mm further ahead.

Because light radiates in a plane perpendicular to the diffracting edge, the pattern that appears on the display screen is two interference patterns crossing each other to form an "x" like pattern. The one sloping from the top left down to the right bottom is associated to with the right barrier and the one sloping from the left bottom up to the right top is associated with the left barrier.

The first possible anomaly appears just outside the center where the two patterns are still in close approximation. The bans from both patterns extend towards each other to form a com on ban as if mutually attracted.

The second anomaly is in the type of pattern. Even though all of the light in each pattern has clearly been diffracted from only one edge, the configuration of the patterns is that for the acute incidence angle single slit. To have the light from both edges interfere in classical wave theory the light would have to lie in the same plane and for interference to occur in quantum theory the light from the two edges would have to have points of convergence.

This can be clearly demonstrated by alternately removing one of the barriers. When the right barrier is removed the pattern changes drastically with the larger bans becoming a single streak and the right bans becoming extremely fine. This also occurs when the right barrier is the sole barrier but even more dramatically as the large and fine bans change sides ( with the left barrier removed it has become the father barrier in a slit pattern with the opposite laser aperture edge ).

With both barriers in place there are other clues in the interference pattern to indicate an acute incidence angle single slit pattern in addition to both patterns having their large bans on the left and their fine bans on the right and at the correct relative spacing. The bans away from the center on both sides lean back towards the center relative to the pattern axis. This indicates that both edges of the slit where a factor in each interference pattern.

This is because the narrower the slit opening the broader the pattern spacing. The two slopping barrier edges create a "v" shaped opening. So the bans would look like segments of an inverted "V", becoming tighter towards the top of the slit opening where it becomes wider.

The third possible anomaly is that the origin for these two patterns emanating from the same slit appears to be different. The pattern from the right slit is slightly more compact than that for the left slit. If the screen is moved 40mm closer to the laser ( the distance between the barriers ), then the spacing in the right slit pattern matches that of the left slit pattern at the farther distance.

This seems to indicate that the patterns originate at their respective barriers. This can be demonstrated further with two additional barriers with plumbed edges placed at least 3m ahead of the left, or farther, beveled edge barrier, with each being 10mm from the laser path on opposite sides. This crates a centrered 20mm gap ( the interference this gap causes if a ban hits a gap edge is so faint and minuscule that it can be ignored in this experiment ).

When the gap is in place the right barrier pattern extends father to the left indicating that it is interring the gap from the right. The left barrier pattern extends farther to the right indicating that it is entering the gap from the left. Finally if the screen is placed at different distances, and the pattern lengths are measured, and the measurements are analysed using simple trigonometry, the apex or angle point for each pattern falls on it associated barrier.

In summary: the apparent attraction between similarly oriented bans in close proximity, generation of a slit pattern by photons only associated with encountering one edge, and separate photon path origins for patterns through the same slit appears at first glance to be a huge anomaly. It seems that the photon path passing the first barrier edge is affected at that point by the farther barrier edge and that the photons passing the farther barrier edge at that point are affected by the trailing barrier edge. The pulling together of photon bans in close proximity also raises the possibility that a single slit interference pattern is really a composite of two separate patterns.

Sketch of Experiment with Actual Pattern Tracings ( phantom line bans lie outside of gap but are neede to show outer ban lean )

Caculations

Drawing Photon Paths According to Existing Theroy and According to Measurements ( added for clarity )

Looking forward to some interesting comments.