Optical: systems and elements – Single channel simultaneously to or from plural channels – By surface composed of lenticular elements
Reexamination Certificate
2002-05-09
2004-06-29
Mai, Huy (Department: 2873)
Optical: systems and elements
Single channel simultaneously to or from plural channels
By surface composed of lenticular elements
C359S621000
Reexamination Certificate
active
06757106
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an optical lens, optical lens unit, stacked type optical lens, optical system, and semiconductor laser apparatus which act on each of the rays of light emitted from a light-emitting unit which is a plurality of light-emitting devices arranged in an array, and in particular, relates to an optical lens, optical lens unit, stacked type optical lens, optical system, and semiconductor laser apparatus which collimates and condenses each ray of light.
2. Related Background of the Invention
An optical lens collimates (parallelizes) rays emitted from a semiconductor laser device as a light-emitting device, and the light is focused onto a minute spot at the light-receiving portion of an optical fiber or the like. The semiconductor laser device often takes the form of a semiconductor laser array, in which a plurality of light-emitting portions are arranged in a row; in this case, the optical lens also takes the form of an array which collimates each of the rays of light from each of the light-emitting portions. Japanese Patent Laid-open No. H7-98402 discloses an optical path converter in which a plurality of cylindrical lenses are arranged in parallel. International Unexamined Patent No. WO99/57791 and European Unexamined Patent No. EP1006382A1 disclose an optical lens for semiconductor lasers in which a plurality of cylindrical lenses are formed integrally. These optical path converters and cylindrical lenses for optical lenses each collimate rays of light emitted from each of the light-emitting portions of a semiconductor laser array.
SUMMARY OF THE INVENTION
As a result of studies of the above conventional type optical lenses, the inventor of this invention discovered that the above conventional optical lenses have the following problems.
(1) Using the optical path converter disclosed in Japanese Patent Laid-open No. H7-98402, it is extremely difficult to arrange each of the cylindrical lenses to collimate incident rays one-to-one with the light-emitting portions of semiconductor laser devices.
(2) In the optical lenses disclosed in International Unexamined Patent No. WO99/57791 and European Unexamined Patent No. EP1006382A1, cylindrical lenses are formed integrally, so that problems such as in (1) do not occur; but there is the problem that, because the depressions and protrusions of each cylindrical lens are exposed to the outside, dirt tends to accumulate in such places, and this blocks light and affects the light emission performance.
An object of this invention is to provide an optical lens, optical lens unit, stacked type optical lens, optical system, which promote a simple arrangement to a position enabling action on each ray of light emitted from each of a plurality of light-emitting portions of a light-emitting device, the light-emitting portions of which are arranged in an array, and which can adequately prevent adverse effects on the light emission performance, and semiconductor laser apparatus.
In order to attain the above object, the optical lens of this invention is an optical lens which, after acting on each of the rays of light emitted from a light-emitting device the plurality of light-emitting portions of which are arranged in an array, emits the rays of light, and which comprises:
one or a plurality of first optical member arrays, each having a plurality of columnar optical members comprising a first optical action portion, which has a curved surface on either the light incidence side or on the light emission side and which acts on each ray of light emitted from each light-emitting portion in the x-axis direction, and in which each columnar optical member is arranged on the same plane; and,
a second optical member, formed in a columnar shape from a transparent material, in the interior of which are embedded in parallel one or two first optical member arrays, along the column axis direction; and, in which
the constituent material of each columnar optical member has a refractive index differing from that of the transparent material of the second optical member.
In such an optical lens, because the first optical member array acting on incident light from the light-emitting device is embedded in the second optical member in an integral structure, arrangement in a position to enable action on each of the incident rays of light can be easily performed.
Moreover, because the depressions and protrusions due to the convex curved surfaces of each columnar optical member, formed by arrangement in an array of each columnar optical member, are covered by the second optical member and are not exposed to the outside, there is no accumulation of dirt on these portions.
Further, the first optical member array is reinforced by the second optical member, and so has excellent strength.
In this specification, “acts on a ray of light” means that the angle of divergence of an incident divergent ray of light is reduced before the ray of light exits.
It is desirable that the columnar optical members be in mutual contact in the array arrangement. In this case, the array pitch of the columnar optical members is shorter than in the case in which the plurality of columnar optical members are mutually separated in the array, so that the lens can easily be applied to a semiconductor laser array which is a light-emitting device in which the array pitch of the light-emitting portions is short. Also, each of the first optical action portions of the columnar optical member acts precisely in the X-axis direction on the ray of light emitted from each light-emitting portion.
Each of the columnar optical members has a pair of contact plane surfaces, formed on the side faces and mutually parallel; it is further desirable that the first optical member array be formed with each of the columnar optical members arranged in the array in mutual contact at the contact plane surfaces. By this means, it is easy to form the first optical member array, and the optical lens becomes inexpensive.
Each of the columnar optical members may be formed integrally. When the columnar optical members are formed integrally, the operation of arrangement of the individual columnar optical members becomes unnecessary, and the optical lens can be manufactured efficiently, and the lens so becomes inexpensive.
It is desirable that the second optical member have a curved surface which acts on either incident light or exiting light. The optical lens comprises two optical members capable of acting on light, so that it is possible to manufacture the optical lens where the refractive indices of the two optical members are set appropriately, and in particular so that the refractive index difference is made large. “X-axis direction” means the direction of arrangement of each light-emitting portion in the light-emitting device when the direction of arrangement of the plurality of columnar optical members and the direction of arrangement of the plurality of light-emitting portions are parallel; that is, “X-axis direction” means the direction of arrangement of the plurality of columnar optical members.
For example, the curved surface of the second optical action portion may be formed at the exit face of the second optical member, to act in the X-axis direction on each ray of light emitted from each light-emitting portion. By this means, it is possible to condense each of the rays emitted from the first optical member array.
As the curved surface of the second optical action portion, either the incident surface or the exit surface of the second optical member is formed into a curved surface, to act in the Y-axis direction on each ray of light emitted from each light-emitting portion. By this means, emitted light is obtained which has been acted on in both directions by the optical lens, in addition to the action in the X-axis direction by the first optical action portion of the columnar optical member. Here, “Y-axis direction” signifies the direction perpendicular to the X-axis direction and to the optical axis.
It is desirable that the thermal expansion coefficient
Hamamatsu Phonics K.K.
Mai Huy
Morgan & Lewis & Bockius, LLP
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