The origin and development of laser

The light source required for fiber-optic communication should be a high-speed modulated light source to carry large-capacity information. Such as lasers and LEDs. The so-called “modulation” is to change the intensity of light, etc., according to the information to be transmitted, to carry information. In 1960, Maimen invented the ruby ​​laser. The difference between laser and ordinary light is that the laser has a very simple optical frequency and has a linear line. In optical, it is called coherent light, and it is most suitable for light source of optical fiber communication. The usual light frequency is very messy and it contains many wavelengths. The usual light frequency is very messy and it contains many wavelengths. The characteristic of coherent light is that the light energy is concentrated, and the divergence angle is small, which is approximately parallel light. After the invention of the ruby ​​laser, various lasers were born: gas lasers, such as helium neon lasers; solid-state lasers, such as YAG yttrium aluminum garnet lasers; chemical lasers; dye lasers. Among them, the semiconductor laser is most suitable for the light source of optical fiber communication. Its small size and high efficiency, its wavelength is suitable for the low loss window of the fiber. However, the manufacturing process of semiconductor lasers is very complicated, and it is necessary to epitaxially grow five layers of doped semiconductor on a substrate material of extremely high purity and defect, and then lithographically illuminate the micron-sized optical waveguide thereon, which has a difficulty compared with the optical fiber. Nothing more than that. In the late 1970s, a semiconductor laser with a long working life at room temperature was finally produced. In 1976, the world’s first practical fiber-optic communication line was established in Atlanta, USA. At this time, the semiconductor laser has not passed, and the light source is a semiconductor light-emitting tube. In the early 1980s, single-mode fibers and lasers were mature, and the superiority of fiber-optic communication capacity was gradually brought into play.
The light emitted by the semiconductor laser is pure, the energy is concentrated, and the beam is very thin. It can efficiently shoot into a single-mode fiber with a core diameter of only 8 microns. Today’s high-speed fiber-optic communication systems use semiconductor lasers as light sources.

True Zero Order Waveplates

The thickness the this type of the true zero-order waveplates or retarders are very thin, the substrates are added to strengthen the waveplates, but in some applications of high damage threshold (>1GW/cm2), the substrates are not allowed, the special carefulness should be taken in operation on such waveplates without substrates.

Hangzhou Shalom EO offer the two types of true zero order waveplates: the singl plate without substrates and the cemented waveplate with substrates. The stocked modules are available for customer’s selection in fast delivery and low cost.

  • True Zero Order Waveplate-Single Plate

This type of zero order waveplate is designed for high damage threshold applocation (more than 1GW/cm2). As the plate is very thin, it’s easy to break during operation.

  • Wide Angle Acceptance
  • Better Temperature Bandwidth
  • Wide Wavelength Bandwidth
  • High Damage Threshold
  • AR Coated, R<0.2%
  • Single Plate

Standard Wavelength:
1/2:1310nm, 1480nm, 1550nm

1/4:980nm, 1064nm,1310nm, 1480nm, 1550nm

  • True Zero Order Waveplate- Cemented

This type of zero order waveplate is constructed of a true zero order waveplate and a BK7 substrate. As the waveplate is very thin and easy to be damaged,the Bk7 plate’s function is to strengthen the waveplate.

  • Standard Thickness:1.1±0.2mm
  • Cemented by Epoxy
  • Wide Angle Acceptance
  • Better Temperature Bandwidth
  • Wide Wavelength Bandwidth
  • AR coating, R<0.2%

Standar wavelength:
532nm, 632.8nm, 780nm, 808nm,980nm, 1064nm,1310nm, 1480nm, 1550nm

Laser Components >> Waveplates >> True Zero Order Waveplates

Hangzhou Shalom Electro-optics Technology Co., Ltd.

Frequently Used Nonlinear Crystal Materials

Frequently Used Nonlinear Crystal Materials

Lithium niobate (LiNbO3) and lithium tantalate (LiTaO3) are materials with a relatively strong nonlinearity. They are often used for nonlinear frequency conversion and also for electro-optic modulators. Both materials are available in congruent and in stoichiometric form, with important differences concerning periodic poling and photorefractive effects (see below). Lithium niobate and tantalate are the most often used materials in the context of periodic poling; the resulting materials are called PPLN (periodically poled lithium niobate) and PPLT, respectively, or PPSLN and PPSLT for the stoichiometric versions. Both have a relatively low damage threshold, but do not need to be operated at high intensities due to their high nonlinearity. They have a tendency for photorefractive effects, which are detrimental for frequency conversion, but are used for, e.g., holographic data storage in Fe-doped LiNbO3 crystals. The tendency for “photorefractive damage” depends strongly on the material composition; e.g. it can be reduced via MgO doping and by using a stoichiometric composition.

Potassium niobate (KNbO3) has a high nonlinearity. It is used for, e.g., frequency doubling to blue wavelengths and in piezoelectric applications.

Potassium titanyl phosphate (KTP, KTiOPO4) may be flux-grown (cheaper) or hydrothermal (better for high powers, lower tendency for gray tracking → photodarkening). The “KTP family” of materials also includes KTA (KTiOAsO4), RTP (RbTiOPO4) and RTA (RbTiAsPO4). These materials tend to have relatively high nonlinearities and are suitable for periodic poling.

Potassium dihydrogen phosphate (KDP, KH2PO4) and potassium dideuterium phosphate (KD*P or DKDP, KD2PO4, exhibiting extended infrared transmission), are available in large sizes at low price. They exhibit good homogeneity over large volumes and have a high damage threshold, but are hygroscopic and have a low nonlinearity.

 

There are a number of borates, the most important ones being lithium triborate (LiB3O5 = LBO), cesium lithium borate (CLBO, CsLiB6O10), β-barium borate (β-BaB2O4 = BBO, strongly hygroscopic, often used in Pockels cells), bismuth triborate (BiB3O6 = BIBO), and cesium borate (CSB3O5 = CBO). Yttrium calcium oxyborate (YCOB) and YAl3(BO3)4 (YAB) are also available in rare-earth-doped form for use as a laser gain medium, and can then simultaneously be used for generating and frequency-converting laser light. Less frequently used are strontium beryllium borate (Sr2Be2B2O7 = SBBO) and K2Al2B2O7 (KAB). LBO, BBO, CLBO, CBO and other borate crystals are suitable for the generation of relatively short wavelengths, e.g. in green and blue laser sources, and for UV generation (→ ultraviolet lasers), because their bandgap energy is relatively high, the crystals are relatively resistant to UV light, and there are suitable phase-matching options. Borates such as LBO and BBO also work well in broadly tunable optical parametric oscillators and optical parametric chirped-pulse amplification.

For mid-infrared (and partly also terahertz) generation, one requires crystal materials with a transparency range extending far into the infrared spectral region. The most important of these media are zinc germanium diphosphide (ZGP, ZnGeP2), silver gallium sulfide and selenide (AgGaS2 and AgGaSe2), gallium selenide (GaSe), and cadmium selenide (CdSe). Gallium arsenide (GaAs) has also become useful for mid-infrared applications, since it is possible to obtain quasi-phase matching in orientation-patterned GaAs .

Sapphire Optics & Custom Sapphire Shapes

Sapphire Lenses, Sapphire Balls, Sapphire Prisms & Mechanical Shapes
Sapphire Optics And Sapphire Custom Shapes, Including Sapphire Balls, Sapphire Lenses, Sapphire Prisms And Mechanical Parts Hold a Unique Place In The World Of Optics. a Sapphire Lens, Ball Lens And Prism All Exhibit Exceptional Performance In a Number Of Applications That Require Extreme Mechanical, Optical, Thermal And Chemical Robustness. Sapphire Optics Also Have Excellent Transmission Bandwidths, Transmitting Well Into The Uv And Ir; a Much Wider Range Than Most Common Lens Materials.

Why Are Sapphire Optics & Sapphire Mechanical Parts Such High Performers?
Sapphire Lenses, Balls & Prisms Are Incredibly Hard, Strong & Wear Resistant:
a Sapphire Lens Can Be Exposed To Extreme Abradants Such As Sand And Particulates With Minimal Effect On The Clarity Of The Optics. This Makes Sapphire Optics The Ideal Material For a Variety Of Applications Such As: Aerospace Lenses, Downhole And Drilling Vision System Optics, Inspection Windows, Watch Crystals And Gun Sights.
Sapphire Lenses And Sapphire Prisms (Optics,Wafers and Crystals >> Sapphire Optics >> Sapphire Prisms) Can Take Pressure Like No Other Clear Material, Making Sapphire Optics The Go-To Transparent Material For Highpressure Vessels, Deep Sea Windows And Sight Glasses. Combined With The Exceptional Thermal And Chemical Performance Of Sapphire, a Sapphire Lens Is The Ideal Transparency For Pressurized In-Process, Deep Sea And Equipment Sensors.

 

FROm: Rayotek Scientific