Bert's Optical Storage

Almost from the invention of the laser, researchers were considering the possibilities of optical data storage. Throughout the 1960s and 1970s, a number of companies were at work on optical data storage systems, held back in large part by the cost and performance level of available lasers. In 1982, Sony Corp. revolutionized the music industry with the introduction of the compact disc (CD). CD-ROM systems for computers quickly followed, expanding the capability of desktop computing. More recently, writable optical disks have been developed, and considerable ground has been gained in holographic data storage technology.\r \r Optical data storage refers to any method of storing data \r using light. The most common method is optical disk, which offers a data density considerably higher than magnetic methods. There are three types of optical disks: ROM, or read only memory; WORM, or write once, read many times; and MO, or magneto optical disk, a disk which, like magnetic computer disks, can be repeatedly written on and repeatedly erased.\r \r For ROM systems, information is recorded on a master disk by pulsed laser. The laser beam is varied or modulated, such that digital data is encoded in the pulses. The beam heats up and distorts a thermally sensitive layer on the master disk, recording a bit of data as a depression in the surface. The depressions are submicron in size, separated by grooves spaced 1.6 microns apart. Once the master disk is created, copies can be produced quickly and cheaply (the cost of a CD is estimated at less than $1). Injection molded polycarbonate replicas made from the master disk are coated with aluminum to increase reflectivity, then sealed in protective plastic. The data retrieval system consists of a low power (3 mW), continuous wave diode laser, a series of optics to focus and circularize the beam before it reaches the CD, more optics to check that the beam is reading the proper area of CD at the correct location, and a detector to decode the signal. The disk spins, and the read head containing the laser and optics scans across it. The beam is reflected from the depressions on the optical disk, and the detector reads variations in the intensity and polarization of the light. These variations are decoded and converted to an electrical signal. In the case of a music CD, the electrical signal is transmitted to a speaker, the speaker diaphragm vibrates, and the result is music. CDs are capable of carrying prodigious amounts of information, over 600 megabytes on a single disk. In addition to the music and film formats, CD-ROMs bring extensive databases to the desktop computer, and the average user's fingertips. World atlases, encyclopedias, and comprehensive periodical indexes are just a few of the CD-ROM products available.\r \r Write once, read many, or WORM systems, are a bit more complicated than ROM systems. Though they have essentially the same optical system for data retrieval, for writing operations they require a more powerful laser and a modified storage disk.\r \r Writable WORM disks are made of different material than consumer CD-ROMs. Typically, a thermally sensitive film is sandwiched between layers of glass or plastic. During the write phase, digital data is converted into an optical signal by varying or modulating a laser beam. The laser puts out about 30 mW of power, since it has to be capable of distorting the write layer. The tightly focused, modulated beam shines through the transparent glass or plastic and hits the thermally sensitive layer, heating it to create distortions that represent bits of data. These distortions are usually either bumps, depressions, or variations in opacity in the material that will make changes in the reflectivity of the surface. To read the disk, the laser/read assembly is scanned over the surface at lower power, and a detector reads and decodes variations in the surface reflectivity to obtain the original signal.\r \r \r \r more

When my husband and I purchased the assets of a small tech business it was necessary to transfer financials, contacts, and sales information asap. We had heard horror stories of corrupted data, etc. We took advice from a colleague and signed on with Bert's. They made the transfer easy. Everything is now well organized and most importantly usable. I'd recommend this company to anyone who needs this type of service. more

I've been a patient of Dr. Petrykowsk'si for a few years. The office staff has never been what I would call friendly, but I've never had a problem with them until now. I went in to get the new lenses for my frames put in, and the brunette at the front counter took them to try to change the lenses. She came back about 10 minutes later, and said that she tried to get the old ones out, but couldn't so I would have to wait for a technician. The technician came out some time later and took my frames back to change the lenses. When she came back out and handed them to me, I noticed that they were bent too wide for my face, so she took them back to fix them. When she brought them back out again, I noticed a gouge in the bottom inside of the frames, and the entire frame was covered with a whitish film. She said she hadn't noticed the gouge, and the whitish color was probably from the cleaner she used. She also said my frames were in poor condition (they're only a few years old, and I only wear them at night). I told her the gouge wasn't there before, and she said that she didn't notice either way. While I was trying to ask about the film on the frames, she turned and walked away. She came back, and continued to tell me that the frames were in really poor condition, and that the whitish film was probably hairspray. I told her I don't use hairspray, and she said it was probably body oil then. The brunette came up, and I asked her about the gouge (she had initially tried to change the lenses). She got very defensive and told me that the gouge was there before, and she didn't do anything to my glasses. They both proceeded to argue with me until I finally asked for my records because I planned to find a new eye doctor. The entire time, Dr. Petrykowski was listening in his office, and not one time came out to ask what the problem was. I stepped inside and told both he & the technician that I've never had such poor customer service, and never been argued with like that. He never even bothered to look up and apologize. The technician handed me my paperwork, said have a nice day, and turned and walked away. Unfortunately, no one at the office seems to care if they've damaged your property, nor do they care about decent customer service. Dr. Petrykowski isn't a good enough eye doctor that I'll continue to go to that practice. more