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We offer a polishing film that is cost-effective and works. *We provide FREE evaluation sample Film when available for Polishing Process evaluation and confirmation. 

Lapping is the removal of material to produce a smooth, flat, unpolished surface. Lapping processes produce dimensionally accurate specimens to high tolerances generally less than 2.5 µm uniformity. The lapping plate will rotate at a low speed of <80 rpm and a mid-range abrasive particle of 5-20µm is typically used. Lapping removes subsurface damage caused by sawing or grinding and produces the required thickness and flatness.

Free abrasive lapping is accurate because of the rigid lapping surface which can be tailored to suit a particular material. Fixed Abrasive Lapping is when an abrasive particle is bonded to a substrate as with abrasive lapping films. Abrasive lapping films have various particles bonded to a thin, uniform polyester substrate and are also capable of producing a very flat surface.

Polishing is the removal of material to produce a scratch-free, specular surface using fine <3µm abrasive particles. Polishing is typically done at very low speeds using abrasive films, or specially designed lapping plates. Polishing with a cloth or lapping plate requires the use of free abrasive, and is a very low-damage process when performed properly. Polishing with a lapping plate is a common process used in the case of metals and hard ceramic-type materials. Polyurethane pads are commonly used for final polishing processes and produce excellent flatness and surface finish. Polishing with abrasive films also produces excellent results. The flatness of the film combined with high removal rates makes them attractive for plate polishing methods.

3M Guide Example (Custom Film Guides Available)

There is a wide selection of abrasives to choose from when selecting a lapping and polishing process. Selecting an abrasive is dependent upon the specimen hardness, desired surface finish, desired removal rate, lifetime, and price. There are four basic types of abrasives that are used in lapping and polishing processes: silicon carbide, aluminum oxide or alumina, boron carbide, and diamond. All of these abrasives have distinct properties and are used for different materials and applications.  Diamond is the hardest material known and has a sharp, angular structure. Diamond is extremely useful in lapping and polishing due to its removal rates and surface finishing qualities. A diamond film can produce excellent surface finishes combined with high removal rates.

Lapping and Polishing Equipment used can vary with the application. Typically what is required for lapping and polishing are the following:

  • A polishing machine with variable speed.
  • A polishing jig (pad) for holding precisely.
  • Fixture holding lapping plates for different applications. e.g LC;MT;
  • Cleaning workstations for controlling fixture maintenance and conditioning.

Connector Endface Preparation Once the optical fiber is terminated with a particular connector, the connector end-face preparation will determine what the connector return loss, also known as back reflection, will be. The back reflection is the ratio between the light propagating through the connector in the forward direction and the light reflected back into the light source by the connector surface. Minimizing back reflection is of great importance in high-speed and analog fiber optic links, utilizing narrow linewidth sources such as DFB lasers, which are prone to mode hopping and fluctuations in their output.

Flat Polish — a flat polish of the connector surface will result in a back reflection of about -16 dB (4%).

PC Polish — the Physical Contact (PC) polish results in a slightly curved connector surface, forcing the fiber ends of mating connector pairs into physical contact with each other. This eliminates the fiber-to-air interface, thereby resulting in back reflections of -30 to -40 dB. The PC polish is the most popular connector end-face preparation, used in most applications.

SPC and UPC Polish — in the Super PC (SPC) and Ultra PC (UPC) polish, an extended polishing cycle enhances the surface quality of the connector, resulting in back reflections of -40 to -55 dB and <-55dB, respectively. These polish types are used in high-speed, digital fiber optic transmission systems. APC Polish — the Angled PC (APC) polish, adds an 8-degree angle to the connector end-face. Back reflections of <-60 dB can routinely be accomplished with this polish.

Again, we offer a polishing film that is cost-effective and works.  Create a FREE CHAT and/or set up a FREE CALL to discuss your application.  All of our support TEAM has been working with polishing, film, and/or interferometry since the ’90s.  *We provide FREE evaluation sample Film when available for Polishing Process evaluation and confirmation. 

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