Patent Publication Number: US-2020277225-A1

Title: Methods of forming laser-induced attributes on glass-based substrates using mid-ir laser

Description:
This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 62/424,227 filed on Nov. 18, 2016, the content of which is relied upon and incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The present disclosure relates to methods of forming laser-induced features on glass-based substrates using a mid-IR emitting laser. 
     Methods of forming laser-induced features on transparent glass-based substrates has been the subject of considerable research in recent years because of the potential for forming desired surface properties on glass-based substrates. Conventional methods have sometimes included directing ultraviolet (UV) wavelengths or CO 2  lasers onto opaque or transition metal containing glass-based substrates to form surface features thereon. These conventional methods have been unable to form laser-induced surface features on transparent glass-based substrates with low transition metal concentrations. 
     Accordingly, a need exists for a method forming laser-induced features on transparent glass-based substrates using a mid-IR emitting laser. 
     SUMMARY 
     According to an embodiment of the present disclosure, a method for forming a feature on a glass-based article is disclosed. In embodiments, the method includes arranging a substrate relative to a laser. In embodiments, the method includes directing a laser beam comprising a light wavelength from about 2500 nm to about 3000 nm from the laser to the substrate. In embodiments, the substrate absorbs light from the laser beam in an amount sufficient to heat and grow a feature from the substrate. 
     According to an embodiment of the present disclosure, a method for forming a feature on a glass-based article is disclosed. In embodiments, the method includes positioning a substrate relative to a laser. In embodiments, the method includes irradiating a surface of the substrate with a laser beam from the laser. In embodiments, the laser beam comprises a light wavelength from about 2500 nm to about 3000 nm. In embodiments, the substrate absorbs light from the laser beam in an amount sufficient to heat and grow a surface feature from the substrate. 
     In embodiment a glass-based article is disclosed. In embodiments, the substrate includes a surface and a laser-induced feature. In embodiments, the substrate absorbs a light wavelength from about 2500 nm to about 3000 nm. In embodiments, the laser-induced feature is on the surface of the substrate. 
     Before turning to the following Detailed Description and Figures, which illustrate exemplary embodiments in detail, it should be understood that the present inventive technology is not limited to the details or methodology set forth in the Detailed Description or illustrated in the Figures. For example, as will be understood by those of ordinary skill in the art, features and attributes associated with embodiments shown in one of the Figures or described in the text relating to one of the embodiments may well be applied to other embodiments shown in another of the Figures or described elsewhere in the text. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The disclosure will be better understood, and features, aspects and advantages other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such detailed description makes reference to the following drawings, wherein: 
         FIG. 1  illustrates laser irradiation of glass-based substrate according to an embodiment of the present disclosure. 
         FIG. 2  illustrates an example surface feature on a glass-based substrate is formed according methods of the present disclosure. 
         FIG. 3  is a plot of a laser tuning curve (laser output power (in Watts) as a function of the laser emission wavelength (nm)) for a laser in accordance with the present disclosure. 
         FIG. 4  is a plot of a laser emission spectrum (W) as a function of the laser emission wavelength (nm) for an example configuration of the laser within the laser turning curve of  FIG. 3 . 
         FIG. 5  is a plot of absorbance curves (%) for wavelengths from about 2500 nm to about 3000 nm for various glass substrates according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs. Although any methods and materials similar to or equivalent to those described herein can be used in the practice or testing of the present disclosure, the exemplary methods and materials are described below. 
     The present disclosure provides methods of forming a glass-based article  100 . In embodiments, glass-based article  100  includes a glass-based substrate  101  and a feature  201  formed on glass-based substrate  101 . Glass-based substrate  101  may include a glass, a ceramic, and/or a glass-ceramic. In embodiments, glass-based article  100  is transparent. In embodiments, glass-based article  100  is colorless. Methods of the present disclosure include forming feature  201  on glass-based substrate  101 .  FIGS. 1A-B  illustrate an example method of forming article  100 . As shown in  FIG. 1 , methods of the present disclosure include arranging or positioning glass-based substrate  101  relative to a laser  400 . Glass-based substrate  101  shown in  FIGS. 1A-B  includes a thickness T between opposite major surfaces  102 ,  104 , and at least one edge  103 . Glass-based substrate  101  may have any shape such as that of a pane, an optical fiber, a rod, a tube, a lens, a mirror, an ingot, a shield, or a filter. Glass-based substrate  101  may also be directly or indirectly coextensive with another glass substrate, such as in a glass-based laminate. Glass-based substrate  101  in  FIGS. 1A-B  is shown as substantially flat for illustration purposes only. Of course, glass-based substrate  101  can be flat, curved, rounded, circular, cylindrical, or other shapes typical of glass-based substrates. Of course, glass-based article  100  may include any number of features  201 , such as 2, 3, 5, 10, 15, 20, 25, 50, 75, 100 or more features. 
     Glass-based substrates of the present disclosure transmit at least a portion of visible wavelengths. In embodiments, glass-based substrates of the present disclosure transmit at least a portion of wavelengths from about 400 nm to about 750 nm. In embodiments, glass-based substrates of the present disclosure transmit about 40% or more of wavelengths from about 400 nm to about 750 nm, or about 60% or more, or about 80% or more, such as 40%, 50%, 60%, 70%, 80%, 85%, 90% or more, including all ranges and subranges therebetween, of wavelengths from about 400 nm to about 750 nm. Visible light transmission (Tvis) at each wavelength from about 400 nm to about 750 nm may not be the same. In embodiments, glass-based substrates of the present disclosure are non-crystalline, inorganic amorphous solids. In embodiments, glass-based substrates of the present disclosure are transparent. In embodiments, glass-based substrates of the present disclosure are colorless. Glass-based substrate  101  may have a coefficient of thermal expansion (CTE) from about 0.1×10 −6 ° C. −1  to about 10×10 −6 ° C. −1  (at about 25° C. to about 400° C.). 
     Referring back to  FIG. 1 , methods of the present disclosure include arranging or positioning glass-based substrate  101  relative to laser  400 . In embodiments, glass-based substrate  101  is arranged relative to laser  400  such that one of major surfaces  102 ,  104  are substantially orthogonal to a laser beam  402  generated from laser  400 . In embodiments, one or both of major surfaces  102 ,  104  of glass-based substrate  101  is positioned at an angle less than 90 degrees with respect to laser beam  402  generated from laser  400 . 
     Referring to  FIG. 1 , methods of the present disclosure may include providing or directing a laser beam  402  from laser  400  to contact glass-based substrate  101 . In embodiments, laser beam  402  has a wavelength from about 2500 nm to about 3000 nm, or from about 2600 nm to about 2900 nm, or from about 2700 nm to about 2800 nm, such as 2500 nm, 2600 nm, 2700 nm, 2800 nm, 2900 nm, or 3000 nm, including all ranges and subranges therebetween. In embodiments, laser beam  402  includes a range of light wavelengths from about 2500 nm to about 3000 nm, or from about 2600 nm to about 2900 nm, or from about 2700 nm to about 2800 nm, such as 2500 nm, 2600 nm, 2700 nm, 2800 nm, 2900 nm, or 3000 nm, including all ranges and subranges therebetween. The wavelengths of laser beam  402  may be predetermined to coincide with an absorbing spectrum of glass-based substrate  101 . That is, the output wavelengths and power from laser beam  402  may be configured to be selectively absorbed by glass-based substrate  101 . In embodiments, the wavelengths of laser beam  402  are predetermined to coincide with the absorbance by a hydroxyl (—OH) concentration within the composition of glass-based substrate  101 . Absorbance by glass-based substrate  101  herein is not photo-induced adsorption conventionally seen in ultraviolet (UV) laser irradiation processes. 
     Methods of the present disclosure may include irradiating one of surfaces  102 ,  104  of glass-based substrate  101  with laser beam  402  from laser  400 . Laser beam  402  may be directed from laser  400  through a lens (optional) or series of lenses (optional) onto glass-based substrate  101 . Directing laser beam  402  onto glass-based substrate  101  is also referred to as “laser irradiation” herein. Laser irradiation is provided in an amount sufficient to heat and grow glass feature  201  from glass-based substrate  101 . The amount or dose of laser irradiation is a function of the laser power output and the time of irradiation. In embodiments, because the present methods do not require photo-induced adsorption, glass-based substrate  101  absorbs light from laser beam  402  in an amount sufficient to immediately heat and grow glass feature  201  therein. That is, growth of glass feature  201  may not include a time delay upon laser irradiation of substrate  101  with laser beam  402  because photo-induced adsorption is not the mechanism for glass feature  201  growth. 
     Laser  400  may output mid-infrared wavelengths. Laser  400  may output a wavelength range from about 1900 nm to about 3000 nm, or from about 2500 nm to about 3000 nm, or from about 2600 nm to about 2900 nm, or from about 2700 nm to about 2800 nm, such as 1900 nm, 2000 nm, 2100 nm, 2200 nm, 2300 nm, 2400 nm, 2500 nm, 2600 nm, 2700 nm, 2800 nm, 2900 nm, or 3000 nm, including all ranges and subranges therebetween.  FIG. 3  provides an example laser  400  tuning curve  401  according to embodiments.  FIG. 4  provides an example laser emission spectrum curve  404  for a specifically tuned laser  400  defined within tuning curve  401  in  FIG. 3 . The laser emission spectrum in  FIG. 4  has a full width at half maximum (FWHM) of about &lt;0.5 nm according to embodiments. Laser  400  may have a power output from about 0.1 W to about 100 W, or from about 1 W to about 50 W, or from about 5 W to about 30 W, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 W or more, including all ranges and subranges therebetween. Laser  400  may include a crystal including chromium (Cr):zinc sulfide (ZnS)/selenide (Se) or a crystal including chromium (Cr):zinc selenide (ZnSe)/sulfur (S). In embodiments, laser  400  may be a continuous wave laser. Laser  400  may be a CL, CLT, or similar series laser from IPG Photonics® or other laser manufacturing companies. In embodiments, laser  400  may be an optical parametric amplifier (e.g., from Coherent Inc.). Laser  400  of the present disclosure is not a short-pulse laser (e.g., with pulsed durations less than 100 picoseconds). 
     During laser irradiation, glass-based substrate  101  absorbs light of laser beam  402 . That is, glass-based substrate  101  is substantially opaque (and therefore absorbing) to wavelengths within laser beam  402 . In embodiments glass-based substrate  101  absorbs light from laser beam  402  in an amount sufficient to heat and grow glass feature  201  from glass-based substrate  101 . Glass-based substrate  101  herein absorbs at least a portion of wavelengths from laser beam  402 . In embodiments, glass-based substrate  101  absorbs at least about 20% or more, or even 30% or more, of wavelengths from about 2500 nm to about 3000 nm, or from about 2600 nm to about 2900 nm, or even from about 2700 nm to about 2800 nm, such as 2500 nm, 2600 nm, 2700 nm, 2800 nm, 2900 nm, or 3000 nm, including all ranges and subranges therebetween. In embodiments, glass-based substrate  101  absorbs at least about 50% or more of wavelengths from about 2600 nm to about 2900 nm, or even from about 2700 nm to about 2800 nm, such as 2600 nm, 2700 nm, 2800 nm, or 2900 nm, including all ranges and subranges therebetween. In embodiments, glass-based substrate  101  absorbs at least about 90% or more of wavelengths from about 2700 nm to about 2800 nm.  FIG. 5  provides a plot of 5 absorbance curves (from about 2500 nm to about 3000 nm) for various glasses for glass-based substrate  101  according to the present disclosure. Lines  1  and  2  are absorbance curves for example alkali-aluminoborosilicate glasses in accordance with the present disclosure. Line  3  is an absorbance curve for an example fused silica glass in accordance with the present disclosure. Line  4  is an absorbance curve for an example aluminoborosilicate glass in accordance with the present disclosure. Line  5  is an absorbance curve for an example soda-lime glass in accordance with the present disclosure. 
     When contacted with laser beam  402  at a location  301 , glass-based substrate  101  absorbs wavelengths from laser beam  402 , is locally heated at a location  301 , and grows laser-induced surface feature  201  from the body of glass-based substrate  101 . That is, glass-based substrate  101  is locally heated at a location  301  (and through at least a portion of thickness T below location  101 ) when contacted with laser beam  402 . The surface feature  201  begins to form as a limited expansion zone created within glass-based substrate  101  in which a rapid temperature change induces an expansion of the glass contiguous location  301  in glass-based substrate  101 . Since the expansion zone contiguous location  301  is constrained by unheated (and therefore unexpanded) regions of glass surrounding the expansion zone, the molten glass within the expansion zone is compelled to relieve internal stresses by expanding/flowing upward, thereby forming surface feature  201 . 
       FIG. 2  illustrates surface feature  201  grown on glass-based substrate  101 . Surface feature  201  is comprised of glass from glass-based substrate  101 . In embodiments, surface feature  201  has the same glass composition as glass-based substrate  101 . Surface feature  201  is a laser-induced surface feature. Surface feature  201  may have a height on glass-based substrate  101  from about 0.01 micrometers to about 1 mm, or from about 0.01 micrometers to about 500 micrometers, or even from about 50 micrometers to about 250 micrometers. In embodiments, the height H of surface feature  201  is distinguishable from thickness T of glass-based substrate  101 . Surface feature  201  may have a width W on glass-based substrate  101  from about 0.01 micrometers to about 1 mm, or from about 0.01 micrometers to about 700 micrometers, or even from about 90 micrometers to about 250 micrometers. The width W of surface feature  201  is measured from opposite locations where sides of feature  201  join with surface  102  or  104  of glass-based substrate  101 . 
     In embodiments, surface feature  201  is localized to an area on glass-based substrate  101 . In embodiments, surface feature  201  is on a fraction of the surface area of glass-based substrate  101 . In embodiments, surface feature  201  is transparent. In embodiments, surface feature  201  transmits at least a portion of visible wavelengths. In embodiments, surface feature  201  transmits at least a portion of wavelengths from about 400 nm to about 750 nm. In embodiments, surface feature  201  transmits about 40% or more of wavelengths from about 400 nm to about 750 nm, or about 60% or more, or about 80% or more, such as 40%, 50%, 60%, 70%, 80%, 90% or more, including all ranges and subranges therebetween, of wavelengths from about 400 nm to about 750 nm. In embodiments, surface feature  201  is colorless. Surface feature  201  may have any cross-sectional shape including semi-circular or parabolic (e.g., see  FIG. 2 ) for example. Surface feature  201  may be a bump, a ridge, or a protrusion on glass-based substrate  101 . 
     Glass-based substrate  101  may include a material (e.g., glass) that absorbs light from laser beam  402  in an amount sufficient to heat and grow surface feature  201  therefrom. Glass substrate  101  may include a material (e.g., glass) with a hydroxyl (—OH) concentration within its composition of 100 ppm or more, 200 ppm or more, 400 ppm or more, 800 ppm or more, 1000 ppm or more, such as 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100 ppm or more, including all ranges and subranges therebetween. Hydroxyl (—OH) concentration of substrates herein may be determined by IR spectroscopy. Glass-based substrate  101  herein may include a soda-lime glass, an aluminosilicate glass, an alkali-aluminosilicate glass, a borosilicate glass, an alkali-borosilicate glass, an aluminoborosilicate glass, an alkali-aluminoborosilicate glass, or a fused silica glass. In embodiments, glass-based substrate  101  may include “wet” fused silica (e.g., Corning HPFS® 7980). Glass-based substrate  101  herein may include glass substrates from Corning Incorporated (e.g., Eagle XG®, Eagle 2000™, Willow®, etc.), Asahi Glass Co. (e.g., OA10, OA21, AQ Series, AQT Series, AQR Series, etc.), Nippon Electric Glass Co., NHTechno, Advanced Glass Industries, PEMCO, Samsung Corning Precision Glass Co., etc. 
     Glass-based substrate  101  may include a glass with a transition metal ion concentration of less than about 1.0 wt. %. Example transition metal ions include arsenic (Ar), antimony (Sb), tin (Sn), cerium (Ce), lead (Pb), titanium (Ti), copper (Cu), etc. In embodiments, glass-based substrate  101  includes a glass with a cumulative transition metal ion concentration of less than about 1.0 wt. %. In embodiments, glass-based substrate  101  is essentially free (e.g., &lt;0.1 wt. %) of a transition metal ion concentration. Transition metal ions within glass compositions may have been used to enable photo-induced adsorption conventionally seen in ultraviolet (UV) laser irradiation processes. Thus, transition metal ions may not be required in glass-based substrate  101  used in methods herein. 
     In embodiments, glass-based substrate  101  may include a glass with an iron (Fe) ion concentration of less than about 1.0 wt. %. In embodiments, glass-based substrate  101  may include a glass with an iron (Fe) ion concentration of less than about 0.5 wt. %. In embodiments, glass-based substrate  101  is essentially free (e.g., &lt;0.1 wt. %) of an iron (Fe) ion concentration. Iron ions within glass compositions may have been used to enable photo-induced adsorption conventionally seen in ultraviolet (UV) laser irradiation processes. 
     In embodiments, during laser irradiation of glass-based substrate  101 , feature  201  grows on a surface  102 ,  104  of glass-based substrate  101  proximate laser beam  402  from laser  400 . That is, glass surface feature  201  may be grown on the irradiated surface ( 102  or  104 ) of glass-based substrate  101 . As shown in  FIG. 1 , surface feature  201  may be grown from substrate  101  on irradiated surface  102 . One or both of major surfaces  102 ,  104  of substrate  101  may be laser irradiated more than one time to form a plurality of features  201  thereon. Of course, surface features  201  may be grown from substrate  101  on major surfaces  102 ,  104  opposite each other in the same or separate laser irradiation steps. 
     Methods of the present disclosure may also include moving or transitioning laser beam  402  along one of surfaces  102 ,  104  of glass-based substrate  101 . That is, methods of forming transparent article  100  may include moving or transitioning laser beam  402  from an initial location to a final location within one of surfaces  102 ,  104  of glass-based substrate  101 . Moving or transitioning laser beam  402  along one of surfaces  102 ,  104  of glass-based substrate  101  may form a ridged surface feature  201  with a length. In embodiments, laser beam  402  is a moved along a length to form a linear feature, a circular feature, a squared feature, a triangular feature, or ridged features of similar shape. Laser beam  402  may also be moved by adjusting a lens or series of lenses between the laser  400  and glass-based substrate  101 . Laser beam  402  may be moved in any direction along one of surfaces  102 ,  104  to form any shaped feature on glass-based substrate  101 . 
     Methods of the present disclosure may also include moving or transitioning laser  400  relative to glass-based substrate  101  or moving or transitioning the location of substrate  101  relative to laser  400 . In embodiments a plurality of individual surface features  201  are formed on glass-based substrate  101  by pausing laser irradiation of glass-based substrate  101  between locations  301 . 
     Methods of the present disclosure may also include terminating laser irradiation of a surface  102 ,  104  of glass-based substrate  101 . Terminating laser irradiation may be accomplished by turning laser  400  off, blocking laser beam  402  from contacting glass-based substrate  101 , or shuttering laser beam  402 . Methods of the present disclosure may include terminating contact of laser beam  402  and glass-based substrate  101 . Methods of the present disclosure may also include annealing transparent glass-based substrate  100  to alleviate or remove thermal stresses therein from laser irradiation. 
     Glass-based article  100  includes glass-based substrate  101  and a laser-induced surface feature  201  thereon. Glass-based article  100  may be included in an OLED display, a glass-based stack, a glass-based sandwich, a lens construct, a laminate, or an ophthalmic build. Glass-based article  100  may be used in stereolithography processes, cameras, ophthalmic equipment, electronic displays, electronic components, human wearable displays, windows (e.g., vacuum insulted glazing), telescopes, vehicles, spacecraft, satellites, telecommunication equipment, or the like. Glass-based article  100  may be transparent and/or colorless. 
     In embodiments, glass-based article  100  includes glass-based substrate  101  and laser-induced glass surface feature  201  thereon. In embodiments, glass-based substrate  101  is capable of absorbing at a wavelength from about 2500 nm to about 3000 nm. In embodiments, transparent glass-based article  100  is fused silica glass. In embodiments, the fused silica glass substrate  101  includes a hydroxyl (—OH) concentration within it composition greater than about 300 ppm. 
     Methods of making glass-based article  100  may include arranging glass-based substrate  101  relative to laser  400 . Methods of making glass-based article  100  may include irradiating at least one of surfaces  102 ,  104 , of glass-based substrate  101  with laser beam  402  from laser  400 . In embodiments, laser beam  402  includes a light wavelength from about 2500 nm to about 3000 nm. In embodiments, glass-based substrate  101  absorbs light from laser beam  402  in an amount sufficient to heat and grow a glass surface feature  201  from glass-based substrate  101 . 
     EXAMPLES 
     The present disclosure will be further clarified with reference to the following examples which are intended to be non-restrictive and illustrative only. 
     Example 1 
     In this example, a 30 Watt CL Series laser (available from IPG Photonics) having a chromium (Cr):zinc sulfide (ZnS)/selenide (Se) crystal was used to focus a continuous-wave laser beam  402  (with a laser emission spectrum curve  404  similar to that in  FIG. 4 ) through a 20 mm singlet lens onto a glass substrate  101  at a plurality of discrete locations thereon to form surface features (e.g., glass bumps). Tables 1-3 below provide the dimensions for each surface feature formed on each of 3 different glass compositions. Table 1-3 also provide the laser settings used to grow said laser-induced features  201  on the glass substrates. Glass bumps  201  detailed below, grown on substrate  101 , were transparent and colorless. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Laser Irradiation of a Spot on Soda-lime Glass 
               
            
           
           
               
               
            
               
                 Laser 
                 Glass Bump 
               
            
           
           
               
               
               
               
               
               
            
               
                 Power 
                 Wavelength 
                 Exposure 
                 # 
                 Height (μm) 
                 Width (μm) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                  8 W 
                 2800 nm 
                 1 second 
                 1 
                 67.5 
                 192 
               
               
                   
                 2800 nm 
                 1 second 
                 2 
                 69.5 
                 192 
               
               
                 10 W 
                 2800 nm 
                 1 second 
                 3 
                 103.4 
                 224 
               
               
                   
                 2800 nm 
                 1 second 
                 4 
                 104.0 
                 224 
               
               
                 12 W 
                 2800 nm 
                 1 second 
                 5 
                 96.4 
                 378 
               
               
                   
                 2800 nm 
                 1 second 
                 6 
                 95.7 
                 372 
               
               
                 14 W 
                 2800 nm 
                 1 second 
                 7 
                 85.3 
                 473 
               
               
                   
                 2800 nm 
                 1 second 
                 8 
                 87.4 
                 455 
               
               
                 16 W 
                 2800 nm 
                 1 second 
                 9 
                 81.7 
                 585 
               
               
                   
                 2800 nm 
                 1 second 
                 10 
                 81.2 
                 585 
               
               
                 24 W 
                 2723 nm 
                 1 second 
                 11 
                 107.9 
                 306 
               
               
                   
                 2723 nm 
                 1 second 
                 12 
                 155.0 
                 205 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Laser Irradiation of a Spot on Aluminoborosilicate 
               
               
                 Glass (Corning Eagle XG ®) 
               
            
           
           
               
               
            
               
                 Laser 
                 Glass Bump 
               
            
           
           
               
               
               
               
               
               
            
               
                 Power 
                 Wavelength 
                 Exposure 
                 # 
                 Height (μm) 
                 Width (μm) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 10 W 
                 2800 nm 
                 1 second 
                 1 
                 27.7 
                 440 
               
               
                   
                 2800 nm 
                 1 second 
                 2 
                 28.2 
                 352 
               
               
                 11 W 
                 2800 nm 
                 1 second 
                 3 
                 24.3 
                 432 
               
               
                 12 W 
                 2800 nm 
                 1 second 
                 4 
                 24.3 
                 474 
               
               
                 13 W 
                 2800 nm 
                 1 second 
                 5 
                 31.2 
                 516 
               
               
                   
                 2800 nm 
                 1 second 
                 6 
                 22.9 
                 493 
               
               
                 14 W 
                 2800 nm 
                 1 second 
                 7 
                 42.5 
                 619 
               
               
                   
                 2800 nm 
                 1 second 
                 8 
                 45.3 
                 671 
               
               
                 15 W 
                 2800 nm 
                 1 second 
                 9 
                 56.5 
                 620 
               
               
                   
                 2800 nm 
                 1 second 
                 10 
                 58.1 
                 640 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Laser Irradiation of a Spot on Fused Silica 
               
               
                 Glass (Corning HPFS ® 7980) 
               
            
           
           
               
               
            
               
                 Laser 
                 Glass Bump 
               
            
           
           
               
               
               
               
               
               
            
               
                 Power 
                 Wavelength 
                 Exposure 
                 # 
                 Height (μm) 
                 Width (μm) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 20 W 
                 2750 nm 
                 1 second 
                 1 
                 10 
                 102 
               
               
                   
                 2750 nm 
                 1 second 
                 2 
                 10 
                 125 
               
               
                 26 W 
                 2730 nm 
                 1 second 
                 3 
                 52.3 
                 171 
               
               
                   
                 2730 nm 
                 1 second 
                 4 
                 33.7 
                 149 
               
               
                   
               
            
           
         
       
     
     Example 2 
     In this example, the same laser from Example 1 was used to focus a continuous-wave laser beam  402  (with a laser emission spectrum curve  404  similar to that in  FIG. 4 ) through a 50 mm singlet lens onto the front of glass substrate  101  along a line to form surface features (e.g., glass ridges). The width of the laser beam  402  contacting substrate  101  was about 3 mm. Table 4 below provides the dimensions for each surface feature formed on each side (front and back relative to the laser) of the glass substrate. Table 4 also provides the laser settings used to grow said laser-induced feature  201  on the glass substrate. Glass ridges  201  detailed below, grown on glass substrates  101 , were transparent and colorless. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Laser Irradiation of a Line on Aluminoborosilicate Glass  
               
               
                 (Corning Eagle XG ®) 
               
            
           
           
               
               
               
               
            
               
                   
                   
                   
                 Glass Bump 
               
            
           
           
               
               
               
               
               
               
            
               
                 Laser 
                   
                 Front 
                 Front 
                 Back 
                 Back 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Power 
                 Wavelength 
                 Speed 
                 # 
                 Height 
                 Width 
                 Height 
                 Width 
               
               
                   
               
               
                 7.8 W 
                 2800 nm 
                 0.78 mm/s 
                 1 
                 17.5 μm 
                 248 μm 
                 8.3 μm 
                 246 μm 
               
               
                   
                 2800 nm 
                  1.5 mm/s 
                 2 
                 21.7 μm 
                 174 μm 
                 6.4 μm 
                 185 μm 
               
               
                   
                 2800 nm 
                  3.0 mm/s 
                 3 
                 17.0 μm 
                 100 μm 
                   0 μm 
                  96 μm 
               
               
                  16 W 
                 2800 nm 
                 0.78 mm/s 
                 3 
                 21.2 μm 
                 160 μm 
                  &lt;1 μm 
                 160 μm 
               
               
                   
               
            
           
         
       
     
     As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a “metal” includes examples having two or more such “metals” unless the context clearly indicates otherwise. 
     Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, examples include from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. 
     Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular order be inferred. 
     It is also noted that recitations herein refer to a component of the present disclosure being “configured” or “adapted to” function in a particular way. In this respect, such a component is “configured” or “adapted to” embody a particular property, or function in a particular manner, where such recitations are structural recitations as opposed to recitations of intended use. More specifically, the references herein to the manner in which a component is “configured” or “adapted to” denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural characteristics of the component. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the disclosure herein. Since modifications combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the present disclosure may occur to persons skilled in the art, the present disclosure should be construed to include everything within the scope of the appended claims and their equivalents.